I have a Boardman CXR 8.9, everything stock except for new mech hanger.
It has a 11-42 cassette with a 11 speed 1x drivetrain. It's Sram Apex throughout, no mixing and matching like in other questions.
The issue is - while downshifting (going from smaller to larger cog) works well, the opposite needs a "nudge" most of the time. The "nudge" could be stopping to pedal for several seconds or pulling the shifter cable and then letting it go.
Already tried to fix my shifting, changed the mech hanger (original was slightly bent) but neither helped. Rear derailleur still seems sticky.
It seems that others had the same issue, but the only suggestion (use a spacer) doesn't seem to apply to me, as it's already there (see picture)
Did I miss something?