I need help understanding what's wrong with my 6 or 7 year old Bird of Paradise Plant.

Background-

7 Year old BOP planted in a 1 foot tall by 1 foot wide pot with drainage. Spring/Summer and early fall the plant is outside and gets afternoon sun and morning shade. In the winter it's been in a window with indirect bright light with about 1 hour of late afternoon sun. It's been thriving and has bloomed the past 3 years and has always been sending up new leaves. The plant is rootbound and the roots are pushing up about 1 inch above the soil. I fertilize with your standard mirile grow about once or twice a month during the summer.

Problem-

This summer has been hot and wet in and the plant has stoped sending up new leaves. A Few leaves which had started to come up are turning yellow/brown and dying. No new leaves have pushed up over the past 3-4 months. It's received a lot of rain and has been wet a lot this summer although there is a drainage hole which appears not to be covered by roots.

What could be wrong with my plant...

To much water

To little water

to much/little fertilizer (basic miricle grow)

To much direct sun

To little direct sun

to much rootbound

Any other ideas?

I don't want to loose this plant as it's been very healthy until recently.

I could take and post a photo if needed.

Thank you