Errors on augments to nodes in groupings

On the parsing of the models of one of our devices, we are getting errors on augments not finding their targets. This is always in combination with nested groupings, where the target is somewhere in the nested grouping.

I've attached a minimal model to this bug report. It is the original model that failed (with some IETF and BBF models), but I've removed everything that is not related to the problem, to have a minimal model to investigate with. I couldn't see an issue with the models however.

Note also that in some occasions the parsing succeeds, and in others it fails. I've not been able to find the environment difference between the 2 systems that would influence this.

I've also attached a file with debug logging from the error.