When something absolutely doesn’t make sense to me I often go back to a point in time and do a checkout of when I was 100% sure “it worked” and if it doesn’t then I assume something external changed, hardware, backend service, the earth’s wobble. If it does work then I will bisect the timeline until I Iocate it. This works for me 99% of the time on tough bugs that just defy any logic. It’s kind of known quantity as opposed to going through endless logs, blames, file diffs, etc. I know in some cases it isn’t really possible but in code that you can have a fairly quick turn around on build/install/test, it works really well.