Service Accounts were removed from the Everyone group as of version 2021-42, and a new Service Account group has been added.
For Service Accounts created prior to this change that are not able to access Alerts and Dashboards, you will need to update them with the new Service Account group.
To check your Service Account for the group it is currently under, click on the gear icon on the left hand side of the screen and click Accounts.
Click on the Service Account you would like to review. From here you can see which groups your account is apart of and make changes to your permissions.
To change the access on one or more Dashboards (or Alerts).
Choose which type of access you want your Service Account to have and add the new group to either View or View and Modify.
Likewise for one or more Alerts,
Choose which type of access you want your Service Account to have and add the new group to either View or View and Modify.