Lightroom freezes when exporting more than 50 images

I have been doing image stacking using starry landscape stacker and need to create tiff files from my raw sony files after a few basic adjustments.  I have all my files imported into LR and would like to just select all the images and convert them to tiffs via an export.  If I have more than x number of images (it seems to varry but anything more than 100 almost always causes a problem) LR will start exporting and at some point just stop and freeze LR.  Unfortunately this seems to end up being more than LR that is effected as I almost always end up having to force the system to quite and then restart.  In my case more than LR means the performance app and even the finder.  This behavior was not always the case but seemed to start after an update.  Which update that was I no longer remember (might have happened when I went to catalina).   This behavior has been going on for a number of OS and LR updates.

System info;

Macbook pro, 16 gig, 512 gig internal ssd, running Catalina 10.15.3

LR  classic 9.2, camera raw 12.2

All my images and LR files are on a 2 terabyte ssd