thennow.

First thing I would do is repot them once more into a much smaller pot. Do use a faster draining mix than peat or coir. Water sparingly to begin with just to keep from rotting the roots. When it starts growing and filling up the pot, then watering may need to be increased. While a plastic bag is okay, I would use a plastic container or glass instead as this will keep the container from touching the leaves themselves.

The pot they are in now is too large and too deep in my opinion.

This 'Pink Diamonds' is in a four inch pot but I keep it in a salad bowl and use another salad bowl as a lid. Most of my rexes do just fine in normal house air (the basement in this case) but this is one I wanted to pamper. (this was shot yesterday)

I am using 12 inch bowls from Party City in this case. The biggest size they offer is 16 inch.

These two rexes are still in their original pots. This is from yesterday. I dribble water in the pots if I see they are wilting or look dryish (never over water them indoors).

The two above were purchased earlier this year at Walmart and/or Lowe's

This is how they looked October 10 before bringing them indoors before Halloween.

The following are some more rexes from yesterday

Anyway if I can do it, anyone can. Nothing too special - watch your watering, use the right size pot, use a good potting mix that drains quick, and give it some light. Watch for mildew attacks as well. You should see results in a couple of weeks.

If the potting medium is unsuitable and the sun damage is not the entire problem then the answer is to entirely replace the potting medium with one that will work.

In your last picture the medium has the same appearance as when a primarily organic mixture has broken down and started to become like muck, with associated inadequate aeration and settling - complete with there being too much of a gap between the top of the pot and the top of the medium.

If the consistency of the medium is a problem in this case that alone will be the basic rooting environment issue and not the size of the pot - commercial growers move huge numbers of various kinds of plants up to significantly larger pots during the production cycle, without problems with over-potting developing.

This time I have made my potting medium of equal proportionz of coco peat and potting soil which, I feel, will keep the soil loose and provide better drainage and aeration of roots. But the problem is the leaves dry before reaching their full size.

Except most of us are not commercial growers on this site... Potting down in winter can be a good idea if a plant is in a pot much too large and you don't have ideal growing conditions like commercial growers.

This 18 inch pot of Caribbean Queen started out as a standard one gallon pot in spring when I bought it. By fall it had filled this pot. Two winters in a very dim, cool garage and it was on its last legs. Today it is in an 6 inch pot and looks fairly well but not the size it once was. Rescue the plant first then worry about size later.