Adult dog losing his training?

Hi all,

So I have an 8 year old German shepherd mix. In the past he’s been so great with going out to the bathroom or alerting when he needs to go. Recently (maybe the last 6 or so months) at every little noise my mom, who lives with us, is convinced he needs to go out. His schedule used to be 6:30am, 5pm and then 10pm almost on the dot. This gradually got moved to 5am, 12pm, 5pm and 10pm -_- he’s now going to the bathroom occasionally in the house whenever we are not home. I’m wondering if all of these new bathroom trips are causing him to lose how to hold his bladder.

He has a current clean bill of health from the vet so I’m not too concerned about it being an underlying issue.

Really just looking for advice on how to get him back to his schedule, or is there a shift as they get older (I didn’t think 8 was that old but he’s my first “my dog my responsibility” dog lol)