@Kh**
they usually tell you to come back within 15 days of your current extension expiring and because you're changing the reasons for your extension (from tourism) to one based on covid there is a good chance they will start the covid extension the day you apply for it <- meaning you will lose all the day you have left on your current stamp if you go too early.
I'd go toward the end of July (but before the 29th obviously)