Externally edited photos won't stack with original in LR Classic

[#1]

I am using LR classic v9.4.  My workflow includes using tools in the develop module to get an image (imported as a DNG) to close to a final edit, after which I use the edit dropdown to finish the edit (mainly sharpening and tagging) in PS.  From PS v21.2.3, I will save the file and a high-res JPEG file on an external hard drive.  These steps typically result in the final saved image being stacked with the original in LR.  However, in the middle of an editing session in which I followed the above steps as usual, I suddenly noticed that my saved edited photos were no longer being stacked on the LR filmstrip alongside the original as had happened earlier in the day.  I checked "external editors" tab under preferences and found that "stack with original" was checked.  I unchecked and re-checked it, but the saved images still didn't stack.  Restarting LR also failed to correct the issue.  Any suggestions?

Thanks, Aaron

[#2]

I am using LR classic v9.4.  My workflow includes using tools in the develop module to get an image (imported as a DNG) to close to a final edit, after which I use the edit dropdown to finish the edit (mainly sharpening and tagging) in PS.  From PS v21.2.3, I will save the file and a high-res JPEG file on an external hard drive.  These steps typically result in the final saved image being stacked with the original in LR.  However, in the middle of an editing session in which I followed the above steps as usual, I suddenly noticed that my saved edited photos were no longer being stacked on the LR filmstrip alongside the original as had happened earlier in the day.  I checked "external editors" tab under preferences and found that "stack with original" was checked.  I unchecked and re-checked it, but the saved images still didn't stack.  Restarting LR also failed to correct the issue.  Any suggestions?

Thanks, Aaron

[#3]

Did you send that image to PS from LrC via Edit in Photoshop?

[#4]

To stack images they all, whether 2 or 10 image files, have to be in the same Folder on your drive.

Saving the Ps PSD or TIF and the JPG files to some other folder than where the original file is stored won't be stacked.

Also If you are creating a JPG from the resulting PSD or TIF from sending a image to Ps from LrC then that JPG LrC doesn't even know it exists.

[#5]

Two things I would look to here:

And you are probably across both of these, but just in case . . .

1. There's a Preference to set in the External Editing tab which pertains to Stacking
   and
2. What is your Sort method in Grid mode toolbar set to?

Hope this can be sorted for you.