Can't update metrics keys

Hello, in 3180, I am unable to update metrics for certain layers. If I set the metrics key, the metrics are “updated”, but to an incorrect value, and then always shown as out of sync. If I manually move the glyph to the matching sidebearing, it works.

I suspect a rounding error.

Glyph when I enter the metrics keys:

I then move all outlines one unit to the right:

Note the left metrics are shown as “in sync” for both 24 and 25 units.

Sometimes even both metrics keys are not syncable.

That is most probably a rounding error. There is a certain threshold to avoid this. On the left, the calculated value is probably between 24 and 25 and the threshold allows both. Not sure why the syncing is not working for the right side. Can you send me the file?

I’m afraid I’m not allowed to. I’ll try and recreate it.