dupeguru intermittently not responding and “Scanning for duplicates” stuck

[ny-native2017]

dupeguru intermittently not responding and “Scanning for duplicates” stuck at 28250905 of matches found (from 1317 groups).

Earlier I tried to run dupeguru overnight on a single drive containing two root level folders that together equal about 3 TB. This is on a Mac and I had three different browsers open and in the morning I saw that dupeguru was not running and sys msg that said "your system has run out of application memory" it showed all the open applications and dupeguru was not one of them.

I shut down the Mac and I'm now running with only mail and chrome running in the background and the scanning for duplicates window seems stuck even though in the activity monitor dupeguru is still active after a period indicating it was not responding.

The type of scan I'm doing is Folders. I am running macOS Mojave version 10.14.6 and I have 16 GB of memory on a MacBook Pro from 2017. Activity Monitor says dupeguru is using 27 gigs of memory.

Thanks in advance for any help.