With the release of Jamf Pro 10.20.0, Jamf has fixed [PI-007508]. This is the PI for DEP Sync failing due to TLS changes being needed for on-prem installs & one which I blogged here.
The fix from Jamf forces TLS1.2 for connections to Apple for DEP/Automated Device Enrollment.
So, if you made a change to your TLS settings as I mentioned in my previous blog post, you can remove those changes.
At dataJAR, we’ve been running all datajar.mobi deployments with no TLS settings enforced via our setenv.sh for a couple of weeks now & all is syncing as expected.