Before we moved here, we lived in a townhouse-style condo, and never had any problems with urine marking. We down-sized, so maybe there was more territorial competition? IDK. Also at that time I only had 2 cat boxes and one was covered...
The peeing didn't stop until I added a third box and took the covers off. All the cats use all 3 boxes now.

I scoop the boxes every morning, and I bleach them and change out the litter every 3 weeks or so.