The colonists continuesly do not use the vending machines. I need to rebuild them every now and then. A guess from @trail locust was the auto-save is the culprit. I tried saving the game manually, restart the game and load the manual save. It worked for a couple auto-saves then. However, the issue is back again even after the procedure.
#Colonists do not use vending machine, starving
velvet wharf
trail locust
The description of this bug is fine.
Mixing in the conversation we had in main chat, I now suspect the actual autosave feature while playing to somehow mess things up.
The issue was fixed like stated above: manual saves and closing game completely.
It is absolute wild guessing that the creation of the next autosave could be causing the bug albeit inconsistently.
A Dev would have to spend time in this ...