Loosened screws around battery access compartment doors

[blkmagikca]

I had just towed the trailer 4 miles to put it on a friend's driveway while our house was being re-roofed and I noticed that the screws around the battery access compartment doors had worked themselves loose and several were about to fall out. I've got a tube of Loctite and I'm planning on putting that on the loosened screws. However, given that I've towed this trailer at least 30,000 miles in the last 3 years without any such issues, I wondering what could be causing this.