Peeing while I’m at work

I have adopted my dog about 10 mo the ago and when I'm go e to work she about once a week pees in the house. Ive tried creating but her seperstion anxiety freaks her out and she destroys the crates (pit bull strength).

it happens when she is comfortable the most I've noticed. I walk her morning, noon, and night consistently. I feed her consistently. I took the beds away and then she pees on the couch or carpet. which are no where the same texture or fabric.

I can't pinpoint what's happening but I'm very broke and had to budget in a vet visit where he said the behavior is to inconsistent for him to say. they did a pee test and she's a healthy girl.

I don't care how silly easy advice you please aid me!