NEW 2107 Enhanced http client connection issues (The reply from location manager contains 0 certificates))

[PH25]

Hi,
I've recently upgraded SCCM from 1809 to 2107 via 2006. Both upgrade steps were in-console.
The pre-reqs for 2107 said I must enable enhanced http, which I have done.

Since then lots of clients are showing grey X's in the console, MPControl.log is showing
"MP has rejected a message from XXXX because the signature could not be validated."

Location services on the clients are showing
"The reply from location manager contains 0 certificates" and "There are no certificates available to install"

I'm worried I might've had the PKI box ticked at some point by mistake when enabled enhanced http, but other than that I'm struggling to find anything useful online about this. It looked like following the steps would create a new SMS issuing certificate in SCCM, but I still have the old ones.

Can anyone help? I'm at a loss and don't really want to revert back to a checkpoint of the old version of SCCM that is way out of date.

Paul

 

[PH25]

It's entirely possible that these are normal messages for our environment and I've only noticed them because I've made a chance, so apologies if I'm confusing matters without reason!