Hi,
Sorry for digging up this old post but I'm experiencing a similar issue when switching from one multi-monitor-layout to my custom one.
It occurs mostly when opening old Projects (from ~2016) that my collegues worked on.
I'll try resolving this the way RameezKhan suggested, however I think it's worth pointing out that a similar issue to what the OP experienced is still occuring, 2 years later.
I'm on a PC running Windows 10 with
-i7 8700 CPU
-16gb Memory
-NVIDIA Geforce GTX 1050 Ti
I'm posting this mostly to make Adobe aware of this still happening
Thanks!