I removed the MDM profile from an 11.0.1 system. Running "jamf manage" reports all the same results in Terminal as a 10.14.6 system. However on the 11.0.1 system, "Profiles" does not show back up in system preferences. I've tried multiple times, reboots, re-enrolling etc. I can remove the profiles from the 10.14.6 system and re-add them using "jamf manage" without issue.
JAMF Pro 10.26.1
I hadn't seen any posts specifically mentioning
jamf manage not working, but the info that Big Sur doesn't allow command line installation of Configuration Profiles has been making the rounds since WWDC 2020 on multiple Mac related sites like Jamf Nation, and the #bigsur channel on the MacAdmins Slack. I'd definitely suggest the latter as a place to look for Big Sur specific issues.