Flowerpot change

This is not a pot problem but a maintenance issue! You are already using a big enough pot for that size of plant (an 11liter/3gallon pot is normally used indoors when not growing in SoG method so the 15 liter pot would be more than enough), and the problem probably comes from not removing the runoff water or leaving it there for too long (the wilting foliage may also be because of that)!! with the fabric pot you are using the root bind your plant is experiencing doesn't usually happen since the roots grow out of the pot and get air-pruned, in this case leaving the runoff water will give the roots good enough conditions to keep growing out of the bottom and bind to themselves (which may cause nutrient uptake issues - nutrient lock), this also can easily cause root rot when they're exposed to a lot of moisture and light. instead of transplanting/repotting try trimming the roots off the bottom of the pot and getting rid of the runoff water right after an irrigation (after checking salinity/EC and pH of course) Hope this helps! Good luck and happy growing :)