Personally, this DTV Extension may end up like the O-X in-country 2nd 5-year extension in that there are also no reports of anyone getting their 2nd 5-year O-X in-country, and rather, they just get a new 5-year O-X at a Thai Embassy/Consulate....
Anonymous participant 335 Yes, I have already watched both English language interviews of the Deputy Director-General of the Department of Consular Affairs (DCA) under the Thailand Ministry of Foreign Affairs (Thailand MFA).
However, if you read the text of the Ministry of Interior Notice signed by the Prime Minister and Minister of Interior published in the Royal Gazette establishing the Destination Thailand Visa (DTV) and the Immigration Bureau Order implementing the DTV Visa, it is very similar to all the other Thai Visas that have been introduced and has a sense of permanancy to it.
Notwithstanding what I have said, it is noted that the Thai Cabinet this week also rescinded all but one type of the SMART Visas, but those other SMART Visa types are redundant with other existing Thai Visas
As with any country's visa policies, there are no truly permanent policies, as even OECD countries update, repeal, amend, change, revise, revoke, and re-introduce various visa types from time to time.
Even though the OP is unclear on several points and a language barrier seems to be an issue here, perhaps it is plausible that the Thai mother and OP had conceived their child outside of Thailand and the Thai mother gave birth to their Thai citizen child inside Thailand.... 🤷♂️🤷♂️🤷♂️
1.) on the Thai E-Visa Website that all Thai Visa applicants must use around the world, a Pop-Up Window will show for anyone that selects Vietnam as their current location and will list the various provinces that the Thai Embassy in Hanoi and Thai Consulate in Ho Chi Minh City have jurisdiction over....
2.) For the Thai Embassy and Consulate in Vietnam, only Visa/MasterCard are accepted on the Thai E–Visa website payment
Did those friends stay in Germany after submitting and making payment for their DTV Thai E–Visa application at the Thai Consulate in Frankfurt, or, at least in Europe throughout the processing time?