Ha ha, great timing. Not that you have a problem of course. What I believe is going on, at least for me, is if I am working on an older scene file, I will have this problem. If I create a brand new scene, the problem goes away. This isn't necessarily a bug, but could also be that in existing scenes, I may have changed some setting somewhere. By creating a new project, that setting is back at its default setting. I haven't figured that out yet.
Try this with a project you are having a problem with. Select EVERYTHING in the Objects Manager and hit Copy. Create a new scene file and hit Paste. Don't forget to activate your render camera as this will come in deactivated. Enable Interactive Viewport and see what happens.
This always works for me. A pain, but it works. When I have more time, I'll see if I can track down the exact cause.