Role Disassociation

We have several roles set up in our Bigfix implementation. There is one particular role that I’ve had in place for several years and it contains about 20 operators. Suddenly I got notified that a third of them weren’t able to access anything in their console. When I checked, the same role was gone for each of them (however not the other 2/3 of the operators in that role). Re-adding each operator to the role and saving the role resolved the immediate issue. However it is super strange for that to happen. There are no obvious errors in the logs. Anyone else have a similar experience? We run 9.5.12 server, relays, and clients.