The 0-3 loss in the last match in group F at the U17 Asian Cup qualifiers on Sunday in fact marked the 17th attempt.
Their last win came in the 2017 SEA Games when the two nations' U22 teams clashed and Vietnam lost 0-3 to crash out early.
Since then Thailand's U16, U17, U19, and U23 teams have failed to repeat the feat.
In 2022 they have lost to Vietnam six times and drew once.
Thailand head coach Pipob On Mo said after the match Sunday: "It's true that we are facing problems in finding young new talent. But we acknowledge that and will find a way."
In 2022 Vietnam have also dominated the Thai women, beating them at the 2023 Women's World Cup playoff, the SEA Games final and the U19 Women's AFF Championships.
Thai newspaper Siam Sport said: "2022 may be the first year in history that Thailand cannot beat Vietnam in any football match. It is an alarming situation."
Vietnam and Thailand may play each other again at the end of this year in the 2022 AFF Cup.