@logicbus I encountered the exact same problem you are describing. Except that I don't know if the site used to have Workbench Moderation, but it's possible.
I deleted the moderation_state field using:
drush config-delete "core.base_field_override.block_content.custom_block.moderation_state"
That solved the problem for me.
Note that your block type might be called something else. You can see all the config names in the "config" database table.