@Norwicensis, we have a new build that might help with your situation. And in either event, would be happy to get your debug log.
(1) Enable advanced debug logging. Go to About, Troubleshooting, and click "Enable advanced logging".
(2) Please install the latest version and reboot https://www.dropbox.com/scl/fi/m4zxfd1ynmw75a991zvpv/Fences6_6.4.1.4-j113-Setup.exe?rlkey=rnfr843eia2eylsv1eygq4ovp&dl=1
(3) After rebooting, modify your layout as desired.
(4) Take a backup snapshot from the Layouts tab to capture the "directly before" state. (Ideally, click on the snapshot and rename it "Before")
(5) Reproduce the issue. (Whatever reproducing means to you; rebooting, or letting a certain monitor turn off etc.)
(6) Once reproduced, take another backup snapshot from the Layouts tab to capture the "after" state. (Ideally, click on the snapshot and rename it to "Broken" or "After problem" etc)
(7) Go to About, Troubleshooting, and click "Create error report package". Be sure to include your forums username and upload per the directions.
Thanks for your help looking into this further