This is probably a silly question….

Have you tried talking to the neighbors?

Is the tree closer to your house than theirs? They may be having similar issues.

It’s nice that your boro will come out and clean out the lines. I’ve never seen that done unless it was an issue at the street. If the clog was on the property, the boro put it on the homeowner to clean out.

(Happened to neighbors in suburban Philly.)