I can see that being a problem. I'll release v2.5.2 shortly with this changed alongside a change to importers I forgot to include.
Once v2.5.2 is installed, you can run the "Rebuild group memberships" action from the Maintenance page to update everyone's group membership records.
They are not coming from a URL, they are requested from CloudWatch nightly during the daily stats gathering, if you have set up an API key in the settings.
Sorry, I'm not sure I understand what you mean by "snog forums or dedicated forums" 🤔 There is an importer and it was tested on v2.1.33 of that addon, so it should work with newer versions as well.
According to my records, you have not downloaded v5.3.0b1 with either of your two licenses, which probably goes some ways towards explaining this discrepancy :)
Remember; Beta versions need to be chosen explicitly the same way you do when downloading XenForo itself: