Every man who has kept a LINE contact from a holiday knows the shape: a burst of messages, then a trickle, then nothing. I have looked at a lot of these conversations. The silence has causes, and most of them are not the one you think.
This is the big one. Her English is spoken and heard, not read. A paragraph of English on a phone screen is work, and work gets put off. Send her Thai and the problem disappears.
Six or seven hours of time difference means your evening is her early morning. A message sent at your nine o'clock is read at her three in the afternoon, after the shop, before the shift, when she is with friends. It gets a short answer or none.
Translated questions read like a form. "Where are you? What are you doing? Who are you with?" arrive, one after another, in a language she has to work at. Tell her something instead. She will ask you things back.
Conversations that continue have a date in them. If you are coming back, say when. If you are not sure, say what would make it possible. A chat with nothing ahead of it becomes a chat about the weather, and nobody keeps those up.
Women who work in Pattaya bars meet a lot of visitors and many of them write afterwards. That is not a reason to give up. It is a reason to be the easy one to read and the interesting one to answer. The ones who get replies are the ones whose messages arrive in Thai and are about something.
You can fix four of the five. The fifth was always true.