Hello, I am not really sure if this is a Lr or Ps problem. My images are not always opening in PS via Edit In Photoshop within Lightroom. I have to shut down my computer and start it up again to get it to work. Not always but often enough that it is a pain.
The fix is usually to uninstall both Photoshop and Lightroom Classic from the CC application (keep preferences), then install first Photoshop, followed by Lightroom Classic. That often fixes this 'missing link' between the two.
Author “Color Management for Photographers" & "Photoshop CC Color Management" (pluralsight.com)