I seem to be able to reproduce this, and it looks like a issue on the backend, so best open a support case. The good news is that the LIST /retentionLabels method seems to work, and the properties are visible therein.
Unable to get retention label by Id
Reshmee Auckloo
20
Reputation points
I am trying the end point from graph explorer to get retention label by id https://graph.microsoft.com/beta/security/labels/retentionLabels/5075e691-ac99-4278-b328-9f89068b25cf
However I am getting message
Internal error occured while calling AdminApi
Please advice if there is any issue with the API currently.