you might try more potassium? HVH recommends lots of potassium for help blooming. and out of curiousity - with the pot in a pot theory is the temp between the pots hotter or cooler than previously? just a thought i had.

Most plants will put blooms on hold when they are hit with high N fertilizer in order to grow the green parts.
You want low N high P (phosphorous).

Stop fertilizing.
Stop watering everyday.
Water in the morning if the leaves are wilting in the morning (not afternoon).

I live in the Philippines and the same is happening to mine cause I hit them with a high nitro fert about 2 months ago. They are lush and green but no blooms and I struggle with the care here cause I cant find info on the tropical weather I now live in, but I have learned through HVH that hibiscus do not like phosphorous but love potassium. Now I will leave them alone for a little while and just water for a couple weeks and begin a half dose of high potassium fert once a week and see what happens. I also use osmocote in the pots so I am not sure if I am over fertilising or under, by the way I am new to the gardening game and would love advise.

What evilscott said. He's right. Stop fertilizing for awhile.