My dog’s strange quirk, that has recently evolved.

My dog, a stray we adopted 9 years ago from the street, always excibited this weird behevior when on walks. Basically he is trying to pee, but he got no more pee. He smells the tree or corner or whatever, then he raises his leg and nothing comes out, because theres nothing to come out. At least this is what he used to do.

Now he started realizing that he didn't mark anything and he tries again and again, until I drag him away, and then moves onto the next thing he tries to mark. One day I decided to just let him keep trying to see how long he would keep at it, and I swear to God, he would keep at it until the heat death of the universe. I sat and waited for him for nearly 10 minutes. For almost 10 minutes he smelled the corner, turned raised his leg and nothing came out, on repeat, until I, again, dragged him away.

I wouldn't count this as a serious behavioral issue, but I am curious to what others think, and of course if I can stop him from doing it.