Updating to Strapi 4.10.2 from 4.3.x gives me a ".at is not a function" error, when trying to edit a post that have relations

System Information
  • Strapi Version: 4.10.2
  • Database: SqlLite
  • Node Version: 16.17.0

The error when trying to edit a post with relations:
TypeError: s.split(".").at is not a function. (In ‘s.split(".").at(-1)’, ‘s.split(".").at’ is undefined)

I have read the migration guides, but don’t seem to find anything that would help with this error.

Does anyone recognizes this and now how it can be fixed?