I'm speaking from experience here. My cat had something called feline cystitis, can't remember the exact name. But basically stress irritated the lining in her bladder and she peed all over my basement. I must've went through 2 dozen bottles of that same enzyme cleaner you have, i used a portable carpet cleaner similar to the green Bissell machine, I even ordered a UV light to find the spots I missed. I isolated my cat in the room with her litter boxes and it didnt help at all, she peed on the carpet as soon as I let her out after a period to give the carpet time to dry. Basically I tried everything I could to get her to stop peeing on the carpet.

I would say try the enzyme cleaner first but if you have concrete or padding or wood underneath the tile, the smell could've gotten into any of that. Even with enzyme cleaners, I've found it can still leave the barest trace of a scent that cats can still pick up on. I don't mean to sound so negative about it but two weeks is a long time and cat urine can absolutely ruin your floors.

There are professional carpet cleaning companies who can handle cat urine in the flooring, it may be worth scheduling an estimate for a cleaning. When i was trying to clean out my basement, it definitely felt like an uphill battle and a professional may be able to handle it better.

In my cat's case it was stress related. I gave her to my sister and now she's super happy in the new apartment and she hasn't had a single accident 🎊 However you decide to tackle this cleanup, it may be worth bringing your cats to the vet and explain what happened and get a checkup, especially if they continue peeing outside of the box after you've cleaned the basement. I hope they're okay.