I'm using MAC OS Catalina on an iMac. In Photoshop 21.2.0, I'm seeing the following issue when sending a file from Lightroom to Photoshop.
If Photoshop is NOT already running, there's no problem in sending the file (say, using CMD-E in Lightroom). Photoshop boots up and imports the file.
If Photoshop IS already running, however, after the file imports and my screen takes me to Photoshop, the import progress bar is overlaid on the imported image. It's frozen at its "start" or "empty" state. Clicking on the bar changes it to "full" (full blue line), but the progress bar remains visible and frozen. Clicking outside the progress bar makes it disappear, though it seems to be just hidden behind the imported image. I've also had Photoshop crash sometimes when all this has happened, though that's not inevitable.
Bug, Crash or freeze, Import and export, Mac, Problem or error