Hi,
Error 0x80090016: Keyset not found. It appears that the issue may be related to the absence of a certificate chain.
Assuming you're utilizing Enhanced HTTP (EHTTP), you might want to refer to this resource: https://www.anoopcnair.com/enable-configmgr-enhanced-http-configuration/ for further guidance.
If your configuration involves Public Key Infrastructure (PKI), it's advisable to verify the presence of Root CA and intermediate certificates on both the client and the Management Point (MP).