LR takes a long time to update its version of a file saved back from PS

My external editing preferences for Photoshop are File Format = PSD.  I set "maximize compatibility" in Photoshop.

If my external editing preferences were a problem, this would happen 100% of the time.  But 99.9% of the time Lightroom updates almost immediately.  The long delay happens maybe once in a thousand.

https://forums.adobe.com/people/J+Isner  wrote This happens occasionally.  I'm wondering if there's a way to avoid it. I have a PSD in the LR catalog.  I Edit Original in PS, make some changes, and save.  The image displayed by LR should reflect those changes quickly, but sometimes it takes as much as ten minutes for LR to notice that the file has changed.  Meanwhile, there's nothing I can do to "poke" LR into recognizing the file has changed. I'm running LR Classic CC 8.2.1 and PS CC 20.0.4 on Windows 7.

Yes that is true. It is because LR creates its own Preview file that is used in the Library module and sometimes it take LR a while to update that preview file.

Go into the Develop module and zoom in on the image. That might force LR to update the preview file. Not sure as I've never tried it.

Have you set the Preferences in Lightroom to reflect this workflow you are trying to achieve?

Preferences / External Editing?

That may help . . .