If you have not restarted your system since you ran locale-gen command do it now.
Check sublime text package installer

Try commenting the above line in locale.gen - then run the locale-gen command - and repeat number 1 and 2.
Change ~/.config/plasma-localerc to read LANG=en_US.UTF-8 - this change only requires a logout - then login and repeat number 2.

When you have sublime text working as expected - you can reapply your language specific configuration - and only one at a time - restart if necessary - check sublime text - and when it breaks - you know why.