F6 key is defined as "Replay from Start" (since Modplug Tracker era). If you want to loop the pattern, check "Loop Pattern" and use the F7 ("Play Pattern from Start") key or remap both keys in the "Setup" -> "Keyboard" -> "Global keys".

As StarWolf3000 says, the default action for F6 is "Play song from start". When reporting a bug or asking a question, please always specify the keyboard action and not the shortcut. Maybe you were previously using a different keyboard mapping?

That depends on keyboard mappings, thats true, and function "Play Pattern from Start" not work correctly. Pattern must loop automatically.

"Play pattern from start" (default: F7) works just fine here. Does it happen with all modules? If not, please provide an example module this is happening with and your mptrack.ini / Keybindings.mkb to analyze.

OK, I reset keyboard mapping to default, now all work in your way. You can delete this topic.