Images in full screen won't load (appear blurry and out of focus)

Hi.

Wondering if there are any solutions to this issue.

With the new update in LR, all images appear blurry (out of focus), especially when viewing full screen.

It shows "loading" for about 10-15 seconds, but even after that, the images don't appear clear.

I thought I botched my entire session until I realized it was just Lightroom.  If I export the images, they are tack sharp.  Needless to sayt his is an issue.  

Until they get this bug fixed, is there a way to return to the previous version, while keeping the catalog intact (not sure how that's going to work).

I know it's not my iMac Pro, because I can edit just fine in Photoshop, and this has not been an issue until the update.

Thanks in advance for any troubleshooting tips. 

(Shame on me for updating so quickly.  I normally give Apple and Adobe 6 months to work out the bugs before I update.  ARGH!)