The instances aren’t lost then, they just aren’t showing. Your ADS seems out of date, so follow this guide to make sure that everything’s all up to speed:
https://discourse.cubecoders.com/t/how-to-update-amp-to-the-latest-version/2297
If the instances still don’t show after that, then copy and restore one of the old instances.json files under /home/amp/.ampdata as the amp Linux user