Hey guys.
I’ve had the same problem but couldn’t go for the solution to disable my thunderbolt ports as I need them for music production. I think now the thunderbolt adapter in my case IS NOT THE ISSUE!!! Neither a defect logic board.
Let me tell you this. For me it was the DEFECT LID THING!!!! My MacBook thought that it was closed and went into “sleep” with an open lid. DUH! No Kernel Panic, no defect logic board nothing like it.
I disabled it as it was suggested in this forum in preferences>energy>battery>turn display off when on battery power……AND SET IT TO NEVER!!!!
WORKED!!!! Haven’t had a shutdown since!
BLESS THE QUEST
Hope it helps!!!
Sebas