Creating enhanced gets stuck

Are we referring to Raw image files or tiff, jpg or mixed?

On my system I tried two raw files with just basic edits the process took 25 seconds for each file.

I experienced the same with a photo that was synced via cloud storage. Tried another one, that was just on my HD - that worked fine.

Everyone with this issue.

I recommend that you post the  issue  over at the official feedback site.

Actually, as a member has already posted such, I recommend you add to the existing discussion

The OP of that posting has not stated much, I do not even know the members OS

But adding on to a discussion at the feedback site gets Adobe Tech attention

Also, Adobe Techs monitor that site.

Existing link is:

https://feedback.photoshop.com/conversations/lightroom-classic/locking-up-during-creating-enhanced-dng-for-anyone-else/60dfc130b845766e19a11663

Recommend that you include your system info as LrC reports it. The most useful is probably that info from first line down to and including plug-ins. 

I also know that this photo showing the program in the process of getting ready to do one picture is a bit different looking than the 10 second estimate on a few of the sample pics they provide for the "near instant" enhanced/enlarge.

I also noticed that if I am enhancing a photo from within a collection that it doesn't add the new photo to it.  I have to select the All Photos group to even see the new one afterwards.  This is after shutting the preview window that never seemed to indicate the process having gone past about 80% much less finishing.  Makes the creation / comparison sequence cumbersome.

I'm afraid I know literally nothing about the Mac. I'm just using an old HP Pavilion PC. Have no suggestions for you. Sorry. But if we keep bumping this discussion to the top, maybe someone will have a good suggestion.

Exact same thing happens to me. I'm on a 2017 MBP with 16g, ram, running Big Sur. I have the latest version of light room classic. 

You might, as an experiment, try disabling the graphics processor in the Lightroom preferences and see if that makes a difference. I don't have a graphics card in my computer.

How long does the progress bar get stuck? I'm using a very old outdated HP Pavilion desktop computer with just 8 GB of RAM. It takes about 5 min. for it to complete creating an enhanced DNG image. Yes, it seems as though the progress bar gets stuck. Could this be the situation in your case?