Oopsie, I was wrong.
I owe you a correction on the version, and that one is on me. I said 8.3 ships 9.2.18, but I was reading the spec file on the branch rather than what you actually get from the stable repo.
Your yum check-update output answers it better than I did: stable leaves you on 9.2.16, and 9.2.18 only turns up once xcp-ng-linstor-testing is enabled.
The screenshot in that same post is the part the still puzzles me. XO says "All good, patches up to date" while the module underneath is two point releases back, which I assume is what everyone else running XOSTOR sees too. If the connection-teardown fixes you found really are in 9.2.19, that is three releases of distance on the exact code path your traces land in, not the single bump I described.