It should also be mentioned that miniature (or any kind of) roses do not take well to being grown inside, period. You would join the very, very long list of people, many of whom might be much more experienced than you, who fail with this plant once it's brought inside. It can be done, absolutely, but it takes some knowledge of just what these plants need and how to provide it, inside. Most roses are fully deciduous plants, or want to be. They prefer a cool (or even cold), dormant period after their leaves drop. Just as any deciduous plant would do, they suffer and complain when their natural cycle is completely disrupted. The watering of any indoor plant needs to be done 'as needed' rather than by a calendar schedule. Most people use their fingers to test the dampness of the soil under the surface. You can also use a small wooden dowel rod...if it comes out damp after being inserted, don't water. Many people learn to tell by simply lifting the container and judging the need for a good watering by the weight. That takes experience. It's imperative that the potting medium be one that drains rapidly so that you can water thoroughly every time, no little sips. Watering frequency depends upon: the type of plant, size of plant in relationship to the pot, type of potting medium, time of year, temperature and relative humidity of the room, duration and quality of light, and type of container, just to name some of the factors. Not only did the temperatures change, but so did the duration and quality of light. Seasonal differences are extremely meaningful to plants. Your rose may have been able to languish on the window sill in the summer, but once fall came around, it was simply unable to even do that anymore. No amount of fungicide of any kind can 'fix' this kind of problem. Roses like plenty of direct sunlight. You cannot provide that, even on the sunniest window sill. Luckily, there are artificial lighting kits and lamps for those of us who wish to grow those kinds of plants needing more light than can be found inside the home.

I don't see any pics, it says they are unavailable, FYI.

Firstly, I would not worry about the brown leaves since all the new growth looks perfectly healthy. Secondly, the roots appear to be rather twisted and the tree is planted rather shallowly. I imagine this is the consequence of its having been confined to a pot previously. Counsel of perfection would be to dig it up, rearrange the roots and replant deeper. Leave off with the fertiliser. Lastly, the stems do look a bit rugged. Bay has quite visible lenticels and imo that is most likely what you are seeing, especially since the tree looks quite gnarly and elderly despite its size. I suspect the confinement in a pot has dwarfed it. If the marks are scale they will be easily removable with a fingernail. Are they?

And move it in front of the window too. It's not getting any light where it is and likely shedding leaves. but yes, try house plants. Your fig is not edible.