I'm having this issue (and I just end up rebooting my PC) that happens when I click on a clip and make a change in the effects controls, it makes the change but completely unselects the clip (or at least changes the effect controls to blank window like the clip was unselected), then I have to re-click the clip I was operating on. I have to do this for every change. So if I click on a click and move it 1 pixel to the left, it will move the clip 1 pixel, but now If i want to make another change I have to find the clip in the sequence again and click on it to reopen the effects controls.
Generally when this happens I completely reboot the machine. I guess I'm just reporting this issue because I'm not expecting no immediate fix.
Crash, Error or problem, Freeze or hang, Performance
If that doesn't work, try resetting the Workspaces: Reset a workspace Reset the current workspace to return to its original, saved layout of panels. 1. Do one of the following: • Click the Workspace menu icon and select Reset to Saved Layout. • Choose Window > Workspace > Reset to Saved Layout. from here: https://helpx.adobe.com/premiere-pro/using/workspaces.html
If that doesn't work, try Preferences > Audio Hardware and set Input to None.
If that doesn’t work, try updating or rolling back your graphics driver directly from the video card manufacturer’s site. If NVIDIA, do a clean install of the latest Studio Driver (NOT the Game Driver)
If that doesn't work, try creating a new project and import the old one into it.