Hi Rejji,
Thanks for the detailed description of when this occurs as well as the additional updates. In addition to my own tests, we have now tested this on systems with AMD graphic cards as well. Still, we are unable to reproduce this behavior nor has it been widely reported.
Until we are able to reproduce this we will not be able to work on fixing the cause of the bug. In the meantime, I suggest making sure that your gpu drivers are up to date and that you try updating to the new UE4.14.1 hotfix release as sometimes an issue will be inadvertently fixed when other issues are addressed.
Thanks for the feedback,
.