If the leading pseudobulbs are nice and plump I would not worry. It is normal for the older pseudobulbs to shrivel back and die off over time. As far as watering is concerned I would recommend that with summer and a nice fresh bark mix in clay pots that watering can be daily without harm but in plastic the addition of inerts such as packing peanuts to the mix might be good and can allow for a lengthened root life with watering scheduled on an alternate day schedule. It all depends on how the mix is holding the water. Water heavy and lift up the pot or even weigh it to get the feel of the heft of the pot when soaked. Then let the pot dry over a few days and then lift it to sense the heft of it. However, this method can give a false sense of security if your mix is broken down so be sure your mix is new, repot every 2 or 3 years as your observation of the condition of the mix warrants.

When I water the catt, the water passes through the mix and its weight is basically unchanged. As I mentioned, the mix is basically all bark, should I consider changing the mix?

Also, I have another catt that has new roots growing but they are all white, is this okay?

Water more heavily, not more often. Give the roots a good soaking and it doesn't matter too much what stays in the medium for Catts. They like to dry out between waterings.

I agree with richardol, do not over water a cattleya. Frequency depends on where you are growing the plant. If it is in a nice humid greenhouse, you don't have to water ever other day. Depends on heat and how fast evaporation.
Catts in my greenhouse, those on the bench are potted in a faster draining mix because of the amount of light they get. The hanging plants dry out faster, so I have them in either sphagnum or a fir bark mix with perlite and ground peat. Some of my plants have been switched completely to my own mix of diatomite, ground coir, fine charcoal and perlite. I do put packing peanuts at the bottom of all my pots.

As richardol pointed out, all old pseudobulbs will shrivel. Some will naturally drop its leaves. As long as the front 3 or 4 bulbs don't. If so, you may have a root problem.

>> When I water the catt, the water passes through the mix and its weight is basically unchanged. As I mentioned, the mix is basically all bark, should I consider changing the mix?

This is normal, specially if the bark material has completely dried out. Sometimes the bark's surface would even repel the water so nothing is seeping into the bark's interior.

Consider switching to a "lower velocity/longer exposure" tactic when watering: Keep the water stream on the potting medium longer to give the bark time to properly soak up the water.
Also, switch to lower nozzle velocity to minimize wasted water that would initially just flow around the bark.

Do remember though, that catts like to dry out in between heavy drenchings.

I have the same issue of barks doesn't seem to absor much of water when running thru the pot, and it's not advisable in the summer when we have draught seasons here in TX just to keep water running. So I ends up just get an old deep container and sit the pot in the water (enough to be even-leveled to the side of the pot) for a few minutes then take it out and drain. It seems to soak up better amount of water this way. And I don't water it again until the bamboo skewer is dry.

I have all kinds of pot collections -- if it's glazed orchid/unglazed azelea pot with holes/slits all over its side, then the water level is even to the rim of the pot; if it's unglazed clay pot but just a single drain hole at the bottom, then the water level is just barely enough to cover the top of the pot but below the base leaves so I don't get water in the crown. If it's plastic, that's when I use the water stream method, since a dry plant in plastic pot tends to capsize when you first set it in the water tub and may dump some medium out if the tub is much bigger than the pot.

When you first pot an orchid with fir bark, soak the bark in water for a few hours or a day. Drain the water and then repot. Dry bark right out of the bag will repell water at first. Again, if you have trouble with the bark drying out too fast, mix in some perlite and ground peat. I don't suggest dunking a pot of orchids in a bucket of water. If you use the same water for different plants, this transmits disease including virus. This was a mistake years ago when people had bad scale or mealy bug problems and would dunk each infested plant into the same insectticide dip. Well, you know what? It takes just ONE virused plant to infect everyone of those other dunked plants. When you do water, use a good watering wand with that has changeable settings on the head. Put it on a nice slow shower and hold soak the plant thoroughly. This takes time if you have a large collection (it takes me a while to get every plant, but it gives you a chance to check each plants health). Yes, water will run through. It should. Water in the morning so the plant has time to dry off. On a hot summer day, you may need to mist the plants several times. But don't do it before nightfall. I keep my fans going 24/7 in my greenhouses so they get plenty of air circulation. So even if they were wet by evening, they dry out during the night, like in the wild.