The same error here.
I was working with 2 databases: Dev_DB and Prod_DB
I switched my local database config to connect to the production database (because we decided to use only the production DB) And when i start the local server i got:
relation "core_store" already exists.
But when I start the strapi in the server terminal with strapi start or even ‘strapi develop’ command - it works fine. Any idea?