@Shirden ***********
as I have plans to retire in Thailand, either on a Retirement or Spouse Visa, I've been very carefully following and taking note of many Posts regarding the two Visa possibilities for most of the past year.
As has already been mentioned, there is a requirement of Insurance with the Non-O A Visa, but there isn't for the 90 day Non-O.
I see the advice of
@John *********
as being good advice - accept the Non-O that you have apparently been mistakenly granted and then before the 90 days that it expires, apply at the nearest Immigration Office for a 12 month Extension. Then each year, before the Extension expires, you can apply for another Extension. John mentioned the requirement of having 800k THB in a Thai Bank account 2 months before you apply for the 12 month Extension. John might correct me on the following, but I believe that the full 800k also needs to be in your account 3 months after being granted the Extension. That's assuming that you will continue with regular 12 month Extensions. If I remember correctly, from 3 months after being granted the Extension, your Bank balance cannot go below 400k and must be at 800k again 2 months before the next Extension. With Extensions, I believe that there's also a monthly income option rather than the 800k, but best not to get confused with that for now.