tastylemonade There was a workaround in the earlier versions to enable cellular data (creating a shortcut widget and setting it to data usage) and it no longer works in the current version.
I can confirm that the Mobile data settings shortcut widget that allowed toggling mobile data in secondary profiles no longer works, it just crashes. There is a github issue about this problem, and under it's duplicate issue it is said that secondary users being able to toggle mobile data is possible, but (in my observation) not implemented as a feature or toggle currenty even if workarounds like the above used to exist:
"Allow for toggling mobile data on/off in secondary profiles.
I think this exists but is disabled by default. We'd need to add a toggle."
Not being able to toggle mobile data in secondary users is a big handicap of GrapheneOS? / AOSP? and now that it has become possible to toggle mobile hotspot in secondary users it would be great to be able to toggle mobile data as well even with the new separate quick settings toggle for mobile data, as such toggle is currently missing for both mobile data and hotspot in sec. users.
I understand that GOS want's to minimize the amount patches on top of AOSP but I believe this would result in such usability improvements that it is worth considering implementing it and maintaining a fix until it is worked on upstream, if and when. I don't know if submitting patches to upstream in currently still on hold or not but maybe getting this implemented upstream would make it easier. Cc GOS devs.