If it's making you feel uncomfortable (it would make me and I'm sure most people feel that way), gather your evidence and talk to someone, police or whoever. They seem to be taking an unhealthy interest. Perhaps they have nothing better to do, but that doesn't give them the right to invade your privacy in this way. Are you friendly with the neighbours on the other side? Ask them if they've had the same experience as that would strengthen your 'case' and make you feel that you're not alone. We had neighbours watching us once and getting up to all sorts of intimidating behaviour. Because of damage being done to our property we had to put up CCTV. It escalated into other things and, after we moved (because of all this) we found out he had mental health issues. I think we realised this while we were still living there and there was nothing we could do. Even had the police visit, but this was for damage to our property. Hopefully, the waving at them idea may stop their weird behaviour. You have a right to enjoy your home and garden.
Blusters in corner if my mouth
Retirement is it what you thought it would be?

