Super minor error here, but when I place lava at the edge of a town, and attempt to pick it up again, I sometimes get a worldguard “You can’t do that message”. The message usually goes away if I move around while trying to pick up the lava, but it definitely is a server side message because I’m getting it in chat. I’ll try to get a video if that’s required.
Can't reproduce, lava placement seems fine on my end at the edge of towns. Try simply moving around and you'll be fine.