Hi Brad,
Thanks for posting your concern in community forum.
Regarding your issue with the latest version of Mac, refer the link below for more information.
https://support.avg.com/SupportArticleView?urlname=AVG-Mac-Legacy-System-Extensions
Regarding your subscription details, I have sent an email as we're advised not to explain in public post.
Please check the email and respond to it for further assistance.
Before the update for iOS installed this week I got an error that AVG would not work with it. Sure enough after the update it is causing all kinds of errors, restarts, and other issues when it runs. So, right now I am paying for service I can't utilize. It is not the computer. Apple warned that the current version of AVG would not work. Will be unsubscribing unless an update for AVG is provided. I looked to see if there was an update and there is not.
We are aware that the Apple guidelines for software developers are changing and we are actively working to improve our products so that they are fully compliant with the upcoming changes. Our transition from kernel extensions to Endpoint Security and Network Extension frameworks is expected to be ready in time for the next major macOS release.
For more details about legacy system extensions, refer to the following announcement from Apple:
https://support.apple.com/en-us/HT210999