Sorry to hear this, and I’m hearing stories like these on the daily now.
My wife, daughter, and I were also warned after our second entrance on a Visa Exempt (both times fully extended). They said that our names were noted in their systems with the warning and that we’d need to get the correct visa next time we try to enter.
Prior to the warning, they pulled us from the airport immigration line and told us to fill out some forms and show them our cash on hand and bank account balance. It was a little strange, but they were respectful.
You should be okay. I submitted as a self-employed remote worker while in Saigon last month, and have been living in Bangkok with a 1-year lease since last July. I'm also from U.S. You have enough funds, just show them as many continuous bank statements of that balance. Keep in mind they my come back and ask you twice to submit those bank statements (they did to me). 2 weeks should technically be enough, if you don't hear back email them a letter in Thai and English with your DTV ID number. I made a post on this the group you can search it there.
I found the search feature ultra helpful in this group. It answered all my questions. Then, after I got my DTV, I added my own unique experience. This seems like the best way for the group to operate: search —> ask (if needed) —> give back
That's because you chose "Genki Native" which is the resident version. You need to select "Genki Explorer" which is the traveler version (we've been using without issue for almost 2 years).