my senior dog doesn’t stop barking

Hi! I have a 14 year old llewellin setter named Jax. He’s the absolute baby of my family. As he’s gotten older we have suspected signs of dementia as he often poops in the house without warning and doesn’t stop barking when left alone for kind of any amount of time. He is walked daily for 30 mintues to an hour (except on the days when it is too cold), we play with him 2-3 times a day, he plays with enrichment toys, and he is given a lot of affection. Unfortunately someone cannot be home with him 24/7 due to school and work. We have a dog walker that comes when we need him which is great. Jax will stare out the windows in our living room and bark repeatedly and he doesn’t stop unless I close all the shades or actively distract him. I can’t take a shower for 10-15 mintues without him nonstop barking. He cry’s constantly even if he’s been walked, doesn’t need to go to the bathroom, has eaten, been played with, etc. When he was younger he would whine and bark a decent amount but nothing to this extent. I really love him so much but it’s difficult to listen to the barking all the time. He’s pretty healthy other than a few minor health issues, he’s active and happy. I am wondering if anyone else with a senior dog has a recommendation for helping with excessive barking and dementia like behavior. I know it’s not completely solve-able at this point in his life and he is seeing the vet soon in the next few weeks. We just started giving him this like doggy neurological treat a few times a week so we will see how that goes. If you have any recommendations or methods please let me know! Anything helps. 🐾