Sometimes even in a room made of wood no large metal objects nearby and then moving a CRT monitor 90 degrees is enough to mess it up requiring it be degaussed.

Sometimes even in a room made of wood no large metal objects nearby and then moving a CRT monitor 90 degrees is enough to mess it up requiring it be degaussed. I'd say the metal frame had ferrous metal in it which is magnetic your monitor was affected by it, I can't see if fixing it. Once removed the source caused your monitor to require degaussing because a large source of nearby magnetism was removed. As to why it wasn't affected right away when it was new my guess is a lot of monitors have built-in degaussing each time it is powered on, so gradually the metal nearby was affected by the degausing coil in the CRT monitor. When metal bed frame was removed the loss of such a large piece of nearby magnetism was too much for the normal start-up automatic degaussing to handle.