Captain, once it happens again please run connection test via NA steam launcher option and send me a message to check it right away.
Captain, captain Jean Delaforet experience another problem not related to issues that affect players from Thailand. In your case changing ISP is not a 100% solution since another player use a different ISP. The problem might be caused by 3rd party ISPs that blocks certain ports on the way from you to EU servers. The fact that another player from Thailand does not experience issues if connection is run by VPN indicates that problem is related to ISP and unfortunately not on our side (thus we cannot help with the issue as we already checked all affected characters).
Could you please call your current ISP support and describe the problem? Also ports that are needed for the game are: 7770, 8089, 5672, 5222, 8080, 21020-21036, 7401-7600.