I'm getting the same issue. It occurs between 21.5 km for me on ascent regardless of TWR, vessel attitude or if I'm flying manually or with SAS on. Sometimes the vessel is destroyed but every time, I notice a "jump" once the vessel reaches 21.5 km (notice the vapor trails in the picture below).
Ascent, just before the jump. I'm not inputting any controls other than using SAS to hold the attitude pointed straight up.
Just after the jump, I didn't touch any controls and notice the vapor trails coming off the fins.
Same thing happened on a different rocket at the same point. I tried removing parts from this rocket to see if I could isolate the issue and eventually I was able to get it to launch without destroying itself, but it would still "jump" at the same point. I then added the parts back until I got to the original design. I was able to get it into orbit without issue but the "jump" in the atmosphere still happens at 21.5 km.
KSP Version - 0.1.1.0
Operating System and version (Windows 10, Windows 11) - Windows 11, version 22H2
CPU and GPU models, any other system information which could be relevant - Intel I9-12900ks, Nvidia RTX 4090
Description of the bug.
Expected Behavior - Vehicle launches smoothly through the atmosphere
Observed Behavior - Vehicle "jumps" passing through 21.5 km, sometimes causing it to lose structural integrity
Steps to Replicate
Launch a rocket
Ascend through 21.5 km
Fixes / Workarounds (if known..)
I kept messing with removing/adding parts until the vessel was able to survive the 21.5 km transition
A list of ALL mods. If the list is long, please consider using a spoiler window.
SpaceWarp Mod Manager
Interplanetary Calculator
StageInfo
Other Notes / Screenshots / Log Files (if possible..)
See above
