Is the answer maybe quite simple:
So Strapi saves content-types in file system.
But Herokus filesystem so far I saw is ephimeral (no experience just saw the description).
If the virtual docker volumes get rebuild all that happened before is gone, cause filesystem is resetted.
If even forceMigration is not set to false than it wipe all unknown content-types from database.
env(“FORCE_MIGRATION”, false),
I spend one weekend to understand how the docker volumes interact with intellijs remote deployment, strapi and my servers (not heroku).
now it works.