So, You're connecting over the VPN to that remote external drive that shared from a computer at a relative's house? If so can you access the share normally from Windows explorer? Are using login credentials on the remote share for access? In other words, how does the remote share know to provide you access? Could be through Windows security or you could be logging in using a user ID password. Are you sure the software is not responding or maybe it's busy doing something. How long did you let it run before you shut down the program?

As far as opening a support case is concerned, I would reach out to support and just explain you don't have maintenance. They can probably provide you some options to get you access to the full support technicians while remaining on your perpetual license.

It's hard to diagnose this particular issue given the lack of technical details around what's going on. Could be security issues, it could be a VPN issue, or it could be something completely else like the agent is doing some kind of work and the latency is very high and that's causing whatever it's doing to take a lot of time. That's something that support team can review in the logs. You can also review the logs yourself if you want. You can check the options dialog in the agent to see the default log location, open it up and examine them. It may point to the operation that's going on at the time you terminate the program.

All great and expected questions.
Yes, this is a remote share on a PC. Both premises are via 100/100Mbps fiber internet.
I did add permissions to the share and can access it remotely.
HOWEVER, I did just find that the share name itself was not what is was before, so I've renamed it - applied permissions, and am crossing my fingers.
Logs don't indicate anything 'not' happening - so I'll let this one spin for a while.
Backup Storage tab shows spinning icon and 'retrieving data' - but no other updating indications of what's happening 'under the hood'.
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As for support, it's worth a try if needed, but I'm not optimistic.
I came to this product after CrashPlan's unfortunate decision to remove self-hosted cloud as an option (even as paid).
If the $29.99/yr. MSP360 Windows Desktop Pro version supports this approach and doesn't break things or require starting from zero, I'd gladly pay it. AND, a VPN accessed remote share would have to be recognized as LOCAL STORAGE (unlimited). I long since grew out of the 5TB limit.
I've not had consistent answers or responses from previous support emails on these questions.

THANK YOU for the quick reply.

is the relative too far away in order for you to grab the drive and do all this work locally like you did for the initial seed?

I should have mentioned I'm using remote access to make changes (Teamviewer).
'All the work' meaning renaming / applying permission?

UPDATE:
I was able to get the backup jobs running on the (now remote) target storage. The issue had to do with network path changes. Ideally the software would communicate better about such things. In fact, the logs show CBB could tell the target folder was probably a CBB backup, so it skipped it.
Once the backup paths were resolved, the jobs seem to run again, however, it's clearly backing up files that were already backed up - thus losing the benefit of the seed backup.
MSP360 won't support my legacy paid software without me first buying the new licensing model and software, yet I don't even know if there's an upgrade path. Paying is not an issue - but throwing money at something that breaks the backup makes me cautious. It appears their focus has shifted to cloud vs. self-hosted / remote repositories.