Thanks for the report, John. You can also demonstrate this bug without using exiftool by changing the metadata, and then reading the metadata, which will also show that the direction is not changed.
This only happened to me for jpegs. Directions were updated correctly for xmp sidecar files.
Hi John, Thank you for reporting this issue and i am able to reproduce this at my end for jpeg images. I have logged a bug for the same and we are looking into this issue.