Is your handgun MAGNETIZED?
I recently discovered that when I put my watchband compass near the slide of my handguns, mostly near the muzzle or grip end, the compass swings in response.
My handguns are magnetized!
I'm guessing that since I observed this among GLOCKs, HKs, even a puny Beretta Bobcat .22, it's gotta be a common thing.
I'm not crazy about magnetic properties in objects or tools that don't use those properties by necessity, but I guess it can't be avoided if it happened without my specifically doing something to cause it, even inadvertently.
Check your guns. Are they magnetized as well?