1) Plants forced into bloom in a greenhouse out of season, typically suffer when moved into home environments which are not as ideal as the greenhouse. The interior of a room is where plants go to die....you are doing your best with southern exposure natural lighting, but it's probably not adequate for long term.

2) The normal cycle is to grow, bloom, set seed, and die down for a rest period. Expect to mature your growth and rest the plant. If in an appropriate zone, plant it into the garden when weather moderates. Otherwise, keep it in a pot and try to get the majority of it's cycle done outside. It'll be much happier outdoors than in.

those are just sheaths yellowing - nothing to worry about.

@JPinNYC, how are they doing now? They don't like to be hot, not above 70F-75F. So hot afternoon southern sun is not the best option.