ee()->db->insert() creates primary key which then does not persist

Hi there,

I am using ee()->db->insert() to insert rows into grid_field tables in an extension I am updating. The insert runs with no problems or errors, and when I use insert_id() to check that new PK’s have been generated they are all present and correspond with the tables. However when I go to check the tables, no new rows have been added?

Any help here would be much appreciated.

Cheers