Thank you for reminding me! I just checked through my LMG file and found this note in it:
I originally got the LMG 400k/40k insurance in April 2020 for my O-A extension at Phuket Immi.
In April 2021 I did the same but, at Phuket Immi., I was given the insurance certificate back.
So that's when I wrote the note to myself to get the insurance in 2022, but not give the certificate to Immigration.
That's what I did and got my O-A Extension without problems this year.
So the question now is, will Phuket Immi. want to see the new 3,000,000 baht insurance certificate next April?