How to stop my chickens roaming
I'd suggest your only solution is fencing your property or building a run for them.
It's likely not just a case of boredom, they will go where the goodies are. If your neighbor has a nice garden the chooks will be drawn to it for all the bugs and choice veggies. It is most definitely our responsibility as Backyarders not to inflict our decision to keep chooks on our neighbors. Good fences make for good neighbors. I personally use this style of fencing for my pasture. Easy setup, easy adjustment, green color blends in with environment making it less visible/obtrusive.
I still have to occasionally wing-clip the serial offenders but it's all a very small price to pay to responsibly exercise my right to keep chooks in MY (and not anyone else's) backyard.
Chickens are creatures of habit, so thats probably why this still want to try and get through the wire.