Similar situation here, I've owned Parallels since v4 (Almost 12 years!) and I'm cheesed a feature I used to have got removed from under me right when I was in a situation to use it. If the Pro-Licence was one-time, I would buy it - but out of principle I hate subscriptions. I don't even use MS Office anymore. (Especially the caveat that once the subscription expires, the software will lock up until you pay up)
In my case, my memory keeps capping out on my Ubuntu VM, causing it to freeze. For those in this thread - if your hardware has flash memory, consider increasing your swap size. Slightly slower, but it dramatically increases your available ram as a workaround. (Also in Ubuntu, it's easy and can be done without restarting).