Comment # 63 on bug 110659 from Michel Dänzer

Can you find out which property is getting set? If there's no (easy) way to get
that out of the kernel, one possibility is to (from another machine via SSH)
attach gdb to the Xorg process while an affected app is running, set
breakpoints in drmModeConnectorSetProperty and drmModeObjectSetProperty, and
get backtraces of where they're getting called from.