This one has kind of made my head explode. Not a complex chamfer in any way, but it's throwing an error about the chamfer no longer being in the model?

Are my chamfers having an existential crisis?

The corners were generated from a surface split, not a repeated feature.

Anyone have any idea what to do with this other than a sweep?

Edit: tried a sweep and got another error! "Unable to offset entities"  Opening the sketch shows no discolored converted lines either.

The anchor made it all go away, but still a very strange bug.

Edit 2: Rolled back to a previous point and did an unrelated edit. Problem now gone. Some weird bug of some kind.