Solved
%VOLM and other global volume variables reporting incorrect value
Weirdly enough, tasker is not reporting the correct volume level on my head unit (Chinese aftermarket). Lots of tasks work normally, but when checking my volume level, it always returns the same value (e.g. 13 VOLM and 7 for VOLS).
Anyone encountered this issue and/or has a lead on how to solve/debug this?