Can I apply for a Covid Extension in Thailand right after extending my visa on arrival?

Life gets so much more easy if you apply directly for a visa that fits your purpose of stay, as you have just applied for the 30 days extension based on tourism you have enough days left to apply for a conversion to a Non Immigrant visa.

and just so you know, you don't have a 30 day visa on arrival <- I say that because there is no such thing as that. 😮 You have what's known as a 30 day visa exempt entry because you showed up here without having bought a visa from the thai consulate before you came BUT were stamped in free without one for 30 days 🙂

Whether you can or can't apply for a covid extension right after you applied for your 30 day extension would be totally up to the immigration office/officer you are applying at

What did they say when you were applying for your 30 day extension when you asked them if you could get a covid extension?

Keep in mind that some offices start the covid extension the day you apply for it as you're changing the reason for your extension from tourism to covid.

So if you just got a 30 day extension and applied for a covid extension you'd lose all the time on the 30 day extension stamp and the 60 day covid extension would start then.