I don’t know whether it will work or not, but if you’ve run out of ideas the “nuclear option” is simple enough, fast enough, and easy enough that it might be worth a try. The idea is to take a perfectly fresh installation of the slicer (maybe on a different computer to guarantee that it’s clean) and then try the print again with one of the generic profiles. The idea behind it is that somehow, without meaning to, some slicer settings somewhere got changed, either unintentionally or without you remembering, and the nuclear option gets you back to something that prints reasonably, even if it’s not optimally.
The other long-shot some people propose is to do a “mesh repair” on your model, even if the slicer isn’t complaining or asking for one. I think that may have worked for me, maybe once. It’s when you’re really scraping the barrel for ideas that one reaches for that one. Probably skip this one, since your benchy is a different model and is having problems too.
Of course, make sure you have all the latest updates installed. I know it sounds too basic to be worth mentioning, but on a different thread recently a seemingly very smart guy had overlooked that and got caught with his pants down. He even very astutely analyzed the problem and reported it as a slicer bug to BBL, and to their credit they responded in less than 24 hours that it had already been fixed and that he should use the current version:
Print dramatically failed, never seen before
As to whether/if any of this makes sense to contemplate, given that your stuff was working just recently and now no longer does, maybe it doesn’t. It’s more in the hail-Mary category. Process of elimination is the fall back when all else fails, but at least none of this is hard to do. Anyhow, I’ll let you be the judge of whether any of it is worth trying or not.
And now I’m out of ideas too!
Edit: Actually, one last idea, load some PLA and slice a benchy and print it with that. If it still looks bad, then try the pre-sliced bench that comes built into the printer. If that prints well, then you can be sure it’s a slicer problem and not a problem with the machine. You have 3 machines all acting up, so it almost certainly isn’t, but again, it’s something easy to try that delivers a hard datapoint and not just theorizing.
Wish I could have been more helpful and that we could have nailed it already. It has me very curious now as to exactly what went wrong. Good luck!