Hybrid exports as Mp4 even if MKV is selected

[InanimateCrbnRod]

As the title says, even if I choose mkv, hybrid outputs an mp4. I think this happened after I enabled passthrough subtitles in config>automation, but I want to pass-through subtitle tracks into the mkv. Any ideas? am I doing something wrong? Thank you for your time.

[Selur]

Wild guess, since you didn't care to read the sticky about what infos to post:
You enabled 'General', but left 'Default container' set to 'mp4', either changing the default output container (to 'mkv') and using 'General' or manually setting an output file with .mkv extension will tell Hybrid that it should output an mkv file.

Cu Selur