Weird mirror glitch

Hey everyone, I’m working on a project right now and I’m having this weird issue with mirror materials on bars. It seems like every single frame it reflects a different image. For what I’m doing, it kinda looks cool, but I would really like to at least know why it’s happening and have the option to make it stop. Here’s a demonstration of the issue, this is 2.49

Also, any suggestions for making the corner texture look better? It’s emphasized by the lighting in this shot, but it looks pretty unimpressive. Any general ideas would be good too.