[Win11 x64 27.0.1 brief] Adaptive formatting seems to have forgotten how to use tabs in C. With a kernel file like the one attached SE happily indents with spaces and it seems to get case indent wrong too despite both being correct in adaptive-stats @ 100%. (Tab indent should also be 8 rather than 4 but thats much harder to guess.)
To reproduce have indent with spaces & indent case from switch set as defaults, load the attached file, go to line132 (should be a case statement) <num+><insert> to copy the line (brief emulation) and it turns up indented too far using spaces rather than tabs.
This isn't new with 27.0.1 it applies to all 27.x, but I've just gone back to working on hard-tab files so its annoyed me enough to winge. (Adaptive formatting seems to be one of the things that rots on regular basis - we've had releases where it is almost perfect then after a while it isn't anymore.)