For the past week, I have been getting this popup whenever I open a PCB in the editor.

Kindy dont place ads inside the editor interfaces.

Anyway here's something interesting to read - Enshittification

Most of the Easyeda users are already jlcpcb customers anyway, there's no reason to show the ads to your existing customers

by the way,
These ads on the home page doesnt affect the user when designing a board, So no issues with this.