Syntax History is a plugin for Sublime Text 3 which stores the history of syntax used for files and apply it when files are reopened.
It detects when syntax is applied to the file by user, saves it in a config file and then use this syntax again when file is reopened.
Install using Package Control:
- Package Control: Install Package
- Select by name
Syntax History
Nothing special, just apply syntax manually to file when it is not detected or detected incorrectly. Next time openning this file you should see correct syntax applied.