Weedy gave you pretty good advice. A typical "fail" is that the cement board is simply nailed or screwed down over plywood. As Weedy mentioned, the cement board should be bedded in thinset, then fastened to the plywood with nails or screws. The bed of thinset simply acts as a void filler between the cement board and the plywood. It prevent micro up and down movement of the cement board. That micro movement can result in popped tiles and cracked grout. With a basketweave, it's be common for the grout to crack and pop out of the joints. But for the individual pieces to crack? Being small, they can usually accommodate some movement in the substrate. I'd take a close look and see if they are indeed cracked, or if perhaps grout got stuck in any veining or fissure lines in the tiles. If the tiles are indeed cracked, that's a problem. It's very difficult to effectively reinforce a floor from below. Floors can flex in one of two ways. The joists can be undersized, so you're getting flex along the length of the joist. Or the plywood can be undersized, so you're getting flex in the plywood between the joists. IF the joists are properly sized, the plywood sufloor should have ben 3/4" thick tongue and groove plywood. Covered with 1/2" thick cement board, thinsetted and fastened in accordance with the manufacturer's installation instructions. As far as the grout in the wall/floor joints all cracking, as fori wrote, those corner joints should be caulked and not grouted. Caulk can flex with movement between different planes. Grout, being rigid, will crack instead of flex.

One thing you might try-- you can get fancy without having to spend big dollars for custom tile. Might cost you a little more for installation, but not nearly as much as some of the pricier custom lines. You've got white tile going in the shower, with dark blue painted walls and a white vanity. Why not continue the nautical theme, and do a grey floor? Do it diagonal in the center, with a blue accent stripe, and then a straight border, somewhere between 3-6", depending on how big your bathroom is?

Home Depot is the only place within two hours that sells the pre-fab, and the colors are horrible. I need three bathroom countertops, and the largest is 52". I should be able to find remnants, but I can't even find fabricators who have remnants. Nobody has a website and the fabricators don't advertise, at all. I found six places in Tulsa, but none of them have quartzite remnants. I can only find stone suppliers. I will make a list of suppliers this weekend, and call them on Monday. Maybe they have a list of fabricators near me. Even Google maps didn't have anyone listed near me. They didn't have the two fabricators that are a half hour away from me. What is your opinion on glossy vs honed in a bathroom. My kitchen has leathered Sea Pearl quartzite, and I love it. I prefer matte colors usually, but I doubt I would like leathered bathroom countertops.

@Amir Ali - I just wanted to post a comment in order to: 1. Let you know that I completely understand what you are going through right now. I have TWO FAILING slate floors that are part of current bathroom renovations. The master bathroom floor had not been grouted due to delays on his part. I discovered that some of the tiles were COMPLETELY LOOSE - and some sounded like they were only partially bonded to the floor. This floor is failing - and it has BARELY been walked on because the bathroom renovation basically stopped due to issues - bathroom isn’t usable so the only use has been when I’ve gone in there to take photos or measure something = maybe some tiles had been walked on four or five times before I started discovering the loose tiles. It is obvious that the tiles failed to bond to the floor - the mortar must have skinned over or something. I am NOT reinstalling the loose tiles. IMPORTANT - my former contractor does not fit the definition of what people here on Houzz love to refer to as a “hack” (at least not the actual business that I hired to do the work) - however, his employee clearly did not know what he was doing (or just didn’t care) - and that makes the owner of the business liable for this work. The business has hundreds of Google ratings (4.9/5), owner is a member of TCNA, I had several reviews from people I know (and trust), and I DID NOT JUST TAKE THE LOWEST BID - I am NOT a CHEAPSKATE. I am so tired of people AUTOMATICALLY blaming the homeowner when they have ZERO basis to do so. Making assumptions and basically telling homeowners that they are IDIOTS and CHEAP really makes me upset. Okay, I’m finished with my rant! 😂 The ”fix” is this: The ENTIRE floor is being torn apart. Not only is the tile being removed, the cbu will be taken out. New contractor assumes that he will also find that former contractor failed to add the required second layer of plywood in order to make sure that the substrate was prepared correctly in order to have a natural stone floor installed. Based upon the above issues, I investigated the slate floor that was installed in one of the other bathrooms back in April. I noticed a few grout issues - and as I went around knocking on each tile, the sound on many tiles indicates tiles that are only partially bonded. This is what the floor looks like from a standing position: And this is what it looks like when I realized that I needed to inspect it after the failure in other bathroom: I have cracks and broken spots of grout in many places. I also have some grout which is stuck on my tile because the contractor failed to seal the tile (as required) prior to grouting (I found this out later - I was in the hospital while this floor was being installed) and made promises over and over to come remedy the issue. So, this floor will also be ”fixed” in the same manner as the first one - I’m just waiting to have it ripped out until after the other bathroom is completely finished. 2. I also wanted to let you know that regardless of whether (i) you have a written contract, and (ii) that contracts specifically provides (or fails to provide) a five year (or however long) warranty period, you still have recourse against the contractor who installed your tile. Most states (probably all but I haven’t done research on this issue in every state) have enacted statutes that protect homeowners for this type of issue. In my jurisdiction, there are specific statutes that relate to home renovation projects - these statues require (among other things) that all work must be done in a good and workmanlike manner. Following industry standards, as well as manufacturer’s specifications, are part of this requirement. Also, the consumer protection act in my state also protects homeowners against contractors who perform shoddy work. I am 99% positive that your state will have some similar statutes. If you want to share your jurisdiction, I am happy to take a quick look in order to point you in the right direction. MANY jurisdictions require the homeowner to provide the contractor with notice and a right of remediation. Unless you follow the requirements of your particular statutes, you won’t be able to bring an action against your contractor to recover damages. FYI - my former contractor has chosen to ignore the notice I provided, so I then was free to hire another contractor to do the remediation work. My former contractor will owe me the money I have to spend to correct his failure to properly install my tile (which will greatly exceed what I paid him - removing tile + cbu + buying new material (including nice slate tile - because I didn’t purchase cheap slate tile for the the project initially). I am sorry that you’re going through this because it is NOT fun. I decided to consider myself “lucky” because he hadn’t yet installed this tile on my laundry floor! Hopefully, you won’t have water damage that will require even more remedial work in order to fix it.