Photoshop crashes when blending a focus stack

Photshop verson 22.3.1

Windows 10 Pro 20H2

AMD Ryzen 5 2600X Six-Core Processor 3.8 GHz

GT1030 GPU on lastest driver

16 GB RAM, 256GB SSD + 2TB hard drive

Simple focus stack on a seashell.  20 exposuers (NEF files) from D850 & 105 AF-S macro lens

Photoshop crashes EVERY SINGLE time on the auto blend.  Just stops responding even if I leave it for hours.  Have tried with a minimal focus stack of 2 exposures.  Still crashes.  Have tried all the usual performance tweaks.  Even turned off GPU support to eliminate GPU as reason for crash.  Don't believe it is memory related as Photoshop is using only 6GB of RAM when it crashes. 

Have run out of ideas.  Problem seems insoluble. 

I see LOTS of similar issues by Googling.  I see NO SOLUTIONS at all 😞 

Has anyone out there solved a problem like this? 

Would I be better off buying a different tool for stack merging?

Thanks for any assistance.