I just skimmed through that post to get an idea, and it seems that this post in the thread gives some Steinberg recognition of the issue:
And your response in that post would seem to confirm you are among those who have some of the special circumstances referred to:
The thing is, when you post a general comment that suggests retrospective record has been broken for a long time, without mentioning those special circumstances, you’ll get a lot of responses like those you’ve got here from people who do not have any of those special circumstances that may relate to this issue. In fact, to add mine:
I’ve used retrospective record a fair bit without problems, and I only started using Cubase at V9.5. In fact, I used it a whole bunch of times yesterday in 13.0.20 with no issues whatsoever, both for grabbing initial MIDI parts while ad-libbing over what I had in my track to that point and then overdubbing controllers (I think just mod wheel) on some of those parts.
But I don’t have any of the special circumstances listed. I was just using a USB-connected MIDI keyboard (Roland A-800PRO).
It sucks that this hasn’t been resolved for those who are using MIDI over LAN, but it might have be more useful if you’d clarified those special conditions in your post, perhaps drawing in more readers who have those same special conditions, where maybe someone would have a way to reproduce the issue, and perhaps helping Steinberg revisit the issue. (I’d probably guess that it may relate to timestamps getting messed up somewhere in the chain of communications, probably only intermittently if it isn’t happening all the time, based on the symptoms. But that is really just a high-level conceptual guess based on the notion that the underlying communications’ being different from the simpler cases like mine.)