I'm having similar issues - few or no delivery scans on ESE items since mid October. I've had a couple in the last few weeks not get scanned AT ALL, which is starting to affect my seller metrics. I'm thinking it might be an eBay issue, because if I check tracking here https://parcelsapp.com/en/carriers/easyship then the packages show as delivered or out for delivery.
What can you do? If a buyer asks where there package is, check tracking on the above link. If you have info, maybe screenshot it and send to the buyer. Or have them go to the site and check themselves. If they request a return, keep in contact but wait until the last possible second to refund. Even if you have to refund, if no delivery scan after 30 days you should be able to collect the insurance.
