So this is obviously a bug and the workaround is cumbersome, but at least works (thanks @Manan_Mehta )
Create a boolean value somewhere for both TRUE and FALSE:
Go to the same table you’d want to write boolean values to by a ‘Set columns’ action and create a Singe value column pulling in the boolean value:
Then assign these instead of typing (TRUE or true, doesn’t matter, it would pass it onto sheets with an apostrophe 
):
My suggestion for a fix would be:
