Doing the "same old, same old” (2,1,3)
I believe the answer is:
in a rut
'doing the same old same old' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for in a rut that I've seen before include "Routinely stuck" , "Locked into a dull and tedious routine" , "Stuck with tedious routine" , "bored" , "Used to dull and tedious routine" .)