Update-
Today I arrived in Bangkok via Suvarnabhmui. The IO asked about health insurance, I presented him my cellphone with a copy of the main English policy of health insurance from my country (not on the form they ask for!).
The IO read the policy for about 10 minutes, photographed the policy, my visa and passport, stamped in until 3/12/2020.
Notice- my health insurance is until mid March 2020. My visa O-A from 10/10/2019.
Good luck to everyone.