Whenever any of you are verbally threatened over sick leave, KPI bullsh1t, uniform violations, delays or any other form of "harassment with a feather", do what so many of us are now doing.
Write the harasser [your manager] an email thanking them for the conversation and outlining the nature and specifics of the "conversation".
Advise at the end of this email that you wish a copy of it to be placed on your personal file and that you'll be retaining a copy for your records.
I can guarantee that the sociopathic, lowlife coward that calls themselves a manager will skulk off to find easier and weaker targets.
It is time to fight back.