As Mario points out in https://www.photools.com/community/index.php?topic=681.0 (https://www.photools.com/community/index.php?topic=681.0), the default "Description" tag has changed in build 108 from Composite to XMP.
But the Default Metadata panel still shows the Composite tag. I did reimport the system metadate layout from C:\ProgramData\photools.com\IMatch5\presets\system.immdl as mentioned in the Release Notes but apparently system.immdl is still configured to display the Composite tag. It makes no difference if I use the "Merge" or "Replace" options.
You're right. Sorry.
I have added instructions here (https://www.photools.com/community/index.php?topic=690.0)