Xr vessel overheating

has anyone found that in LEO, there is significant atmospheric temperature, which is only regognisable by XR-class vessels?

please help as the ships can withstand the temp with idle and no doors open etc, but when i go to open radiators, nosecone/docking port etc, the vessel explodes with a '[area of movement] hull breach at mach11.5ish (orbital velocity)

is this a bug in the XR ships or in the new atmospheric layout?

DG-IV and Arrow by dan steph and all other ships are fine, only XR-vessels have this problem, driving me crazy
works when getting to orbit or loading scenario with vessel in orbit

not sure if the same thing is in GEO, as never been able to get there in XR as vessel explodes...... dont know much about atmospheric composition, but is it something to due with the fact orbiter 2010 has a newly updated thermosphere or something?