It's occur 2 days ago, on my //Test// server (single creative mode). I tried to gif capture it but unfortunately the key for has not engaged so I'll to describe it the more precise.
Timeline :
# I remember had remove numerous various blocks which can be multi-sloted on crafting mode in order to read their informations (mass, etc.).
# Then I put few capsules on the station and shot in their "void/transparent" parts of the blocks in order to see their integrity (confirm if the shots will touch the block or pass through). I destroyed it in that way, so that confirm they were act like real blocks.
# I maybe accidentaly shots the station and/or the ship too during the test process (have to be checked on the log).
# Then I don't remember exactly, maybe I was gone in the build block of the station.
# Anyway I remember go to the "ship" (core+power generator+thrust).
# I forgot if I had suppress all and create new ship or if it was the same but with just let the core.
# I turn back in creative mode.
# **I remember to had make a miss-click and drop a power generator in the space instead of placing it** (the icon of the generator floating in the void very near to the core at its 9.30~11 hours from frontface)
# I can't surely assume if was build mode or astronaut mode because I was too distracted to pay attention to this detail, but at that moment in my mind I was in build mode.
# I put some generators then remove it.
# It's when I tried to put it again on the core that the bug occur, the generator appear and disappear instantly in 0.1 sec.
I tried to place them backface, leftface ; nothing but appear-disappear.
I tried to gif that but it fail (don't know why) and log out because it was very late and too tired to restart. I didn't connect yet since, I'll keep you tune to tell what happen after the reboot. Here the log, that bug occure at the 10 last minutes (may ~20mn in case of you see nothing strange).
{F5782}