Ok - so just like to quick update –
looks like what happens is -Strapi utilizes - stapi_base_folder/src/api/content
content is typically your content manager items - that you sees as lost while server was restarted.
so basically when u create your content -strapi creates folder with controller, routes, DB schema .etc - and each time when server starts it finds the schema from there and tries to recreate / delete if one doesn’t exist
in scenarios when folks find tables/data are deleted - it must be that the content file isn’t commited if another system was used to run the strapi - it would miss those table and recreate the content schema
If you haven’t took the backup – i can say your data is lost , but you can recreate tables if you can access those src/app files – but it still wouldn’t have your data.
Good luck - but these things could have better controlled by strapi then each time scanning and recreating /deleting schema’s sadly
hope if helps