hi dave,
thanks for your private message.
i have checked your rbac version, it 's different from mine. to further check if the issue is related to the server side, please confirm some points below:
- can you assign other admin roles?
- does the error occur if you create another global admin account and then assign the role to it?
- run the command below in the exchange online powershell to check if there is any error message:
new-managementroleassignment -role "address lists" -user *** Email address is removed for privacy *** -delegating
if there isn’t an error message, then run the command below to assign the address list role to your admin account:
new-rolegroup -name "address list management" -roles "address lists" -members *** Email address is removed for privacy ***
note: replace "*** Email address is removed for privacy ***" with your admin account's email address.
if there is an error message after running the command, please upload a screenshot about it for analysis. to upload screenshots, select the use rich formatting button in the forum, and then click insert /edit media like the picture shows below:

tips: please mask your private information in the screenshot.
we will assist you further after receiving the information above.
regards,
larry