Seven years in a crowded pot? I would knock out the plant and see what the roots look like. Small leaves are usually an indication that the plant is not getting enough nitrogen. This may be caused by the pot being so root bound the water and nutrients drain right out the bottom of the container. The drainage hole may be almost completely plugged and the roots may be in standing water, which could give the same symptoms. In either case I would re-pot with new soil. Save the newer roots and discard the older parts in the center. You don't have to use larger pots since your root mass will be smaller. Al

I grew them in Orlando in huge pots. They were left crowded until they broke the terra cotta pot. Then if I thinned them to too few per pot, they took a year or two to rebloom. That's zone 9 in hot and tremendously humid conditions. They were gorgeous in early spring and I could move them to whereever they made the greatest impression. After the bloom was over, they still had beautiful green foliage that looked great as a background for other flowering plants. They didn't seem nearly as happy planted into the landscape, where they flowered less prolificly.

The mystery will be solved much faster if a photo can be provided.

Em..... I can only imagine the lovely flowers since I have not seen the dwarf varieties myself. You may choose to leave the flower stock if the seeds are desired but I am not certain most seedling will produce true to type. This lily clump multiplies rapidly in nature anyway so why bother with seeds. I would cut the flowering stock close to ground level. Often plants pick up a bust of energy and perform best this way. Ankrara's Hobby Corner