Think I may have found a bug with a part in Kerbal Planetary Base Systems - specifically the LV25 'Meerkat' Landing Assist. There is no 'Open Hatch [F]' prompt when I approach the hatch, so I can't pass through. Sorry I can't attach a picture/video to show you!
KSP (21).log
https://forum.kerbalspaceprogram.com/topic/210548-112-freeiva/?do=findComment&comment=4316283