It's not you!
You can for the time being use the link to go back to the "classic" version (9.6) of System Manager. Still fully functional.
I suspect the new version does not have all the hooks in with the REST API to do all the same function yet. Little bits and pieces keep getting added.
Open a case with support. Officially log the complaint. Maybe post the Case number here and have others open similar cases referring to that one. The more visible the problem, the (usually) quicker it may be resolved.