I'm a long-term volunteer in Thailand who previously helped and looked after 170 volunteers in about 15 provinces for 2 sister foundations.
During covid some Foundation connected with immigration and got about 400 volunteers through that one foundation and immigration officer. They basically screwed the system for all real volunteers.
People on these Foundation visas can't actually change to any Visa without expensive extra costs let's just say. And there's been about five people say they can't even get the elite Visa because they were in that Foundation.
There's so many different options for people to stay in Thailand. I know all about Chiang Mai options if you want to know more.
It's all relative to where you want to be based. Generally if you're in one province you need to seek out options in that province. Getting a random visa from somewhere out of the province raises red flags when you visit immigration in the province you live.
Walk in to Airport immigration. Give them both passports and a full photocopy of every stamped page in the old passport and face page of both. You will get a couple of forms to complete.
Hand everything in. Get it back. Usually around 3 stamps and writing in the front page.
MAKE SURE YOU CHECK EVERYTHING AND EXPIRY DATES ARE ALL THE SAME.
Next extension, just in case take both passports as well.