New hires were not being granted permissions for user login despite being members of dynamic groups.
The role based permissions were not being updated after a dynamic group refresh.
1) In Admin Center/Employee Export, do an export.
2) Edit the exported csv file, identify and keep those users in the missing user list, and remove all the other users in the list, and save it.
3) Use the edited file to do an Employee Import.
The employee import triggered a dg refresh job at the end of import job, and that dg refresh fixed the issue.
"Dynamic groups" "role based permissions" "refresh" , KBA , LOD-SF-PLT , Foundational Capabilities & Tools , LOD-SF-PLT-RBP , Role Based Permissions , Problem