I can confirm this behaviour on many of our firewalls as well.
There´s a confusing amount of places where you can see pattern status, such as the firewall´s dashboard, "Scanner Versions" on the Control Center or the AV service´s log file. According to Barracuda support, outdated pattern version might not necessarily mean they´re really old, but you cannot trust. In this current case it seems the patterns are really not updated, in my opinion.
Since I have experienced such issues at least since Nov 2016 (case #01478628) with an ongoing history of fixes and new bugs and new fixes and new bugs etc., I have lost all faith in Barracuda´s ability to really fix these problems.
The last bug was opened in Feb 2019 (BNNGF-36527 - CC Control - Scanner Versions rarely updates) and the last reply I got was in April, stating that Barracuda doesn´t have any resources to fix this bug due to the the planned release of 8.0.1.
Well, while I don´t see any reason to not fix bugs in supported releases anyway, since 8.0.1 is released, maybe Barracuda wants to fix bugs again?