Adult basset keeps peeing indoors overnight

We love our boy, Linus. He’s an amazing brother to our child, he’s the best boy ever. That being said, for a few months now, more or less, almost every night he will wander the living room and urinate on one of our rugs.

We take him out before we go to bed, and immediately when we get up. Between my partner and my sleep schedule he’s usually only left alone for maximum 5 hours.

Does anyone have any suggestions, tips? We’re considering getting a dedicated pee pad.