@stevenjcee Well, I uninstalled Opera, then tried to do a fresh install, and for some reason, it opened with my information still contained, and still froze up within a minute! WTH?
I just updated macOS Monterey to Version 12.3 Beta (21E5227a).
And, Opera Neon is fine now!
For reference, the Opera Neon version in question is 1.0.2531.0 (64-bit).