Werid sync issue when freezing tracks

Yebo people! I just realized that I have this super -weird issue. When I freeze down tracks, they offset maybe -100 ms. All looks like is should, but the sound plays way too soon, throwing all sync right out the window.
What gives? And what can I do to make it jive again? This does not happen in 10.3.10, only in (the latest) 11. Everything is just fine until I try to freeze the stuff, and it appears that the offset is pretty consistent in timing no matter what plugins I’ve used that I can tell right now.

UPDATE: This seems to be a problem when sending Aux to an FX-channel that is routed through a group. Which makes it a huge headache in what I do right now to be totally honest.
Actually, the freeze-function has had several severe issues since at least version 7 that I know of. Another one being that sometimes - with absolutely nothing to tell when or why - it skips the first few seconds altogether in the frozen track and doesn’t even begin playback until a bit into the material. You can get around that by placing a mute region a bit ahead of the actual stuff, but that is not a good thing to have to worry about.
Actually, the engine often takes a lot of time to get to business. Playing a raw file from the pool for the first time after playing timeline almost always results in having to wait a few seconds for the engine to actually output what it’s supposedly playing at the moment. Same goes with the Media Bay. It all behaves very much like a kid with bad self-esteem trying to set the rules for everyone else by refusing to play ball until HE says so, and that can get really super stressful when deadline draw near and there are a lot of real issues that should take up my mind instead.
All of this - except the heavy delay which is new to me (although truth be told I have never worked this way before though) - has been totally consistent between two of my studios with absolutely nothing in common except my Yamaha surround-system, the chassis of the main computer, and the outbord stuff.

I guess… no information on the system, no real answers

Huh, took for granted that that information followed from the old format here… Anyhoo:
This is XEON 8-core, 16 gig memory, Prism Sound Titans, Windows 10 Pro x64 (always updated), Nuendo 11, and the plugins from mainly MAAT, Weiss, Eventide, Lexicon, AudioEase, Babelson, and Newfangled.
Doesn’t really matter though, the first time I remember having a problem with the engine stalling was with a Core2Duo, LynxTWO, Windows 8 Pro x64, Nuendo 7, and mostly plugins from Waves and a lot of free stuff. There has been no change in behavious between these setups in the slow to start aspect regretfully, except that it’s gotten worse over the years.
And regarding the early trigger in frozen tracks - I have never hardwired locations to groups in a project this way before, so I have never had grouped auxes to test on before, but trying the same project in Nuendo 10.3.10 seemed to work just fine as far as I could tell right now.
Dunnu if these things are related at all although they kinda feel so, but they are both big issues to me non the less soooo…

Oh, and I forgot another issue that has been consistent during these years as well - a weird echo that MIGHT be linked to cycling, especially on a really heavy project. IIRC it appeared at the same time as the stalling playback, and means that when freezing a track, the frozen results starts as usual, but after maybe half a minute, it will repeat the exact same thing again. Except the track is often absolutely empty there, and it was only supposed to play once.
As I said, I don’t know if all of these things are interconnected, but if they are, I figured it better to keep them collected here over spreading what might be caused by the same thing over several posts.