if you lose all your land but still have some navies or armies somewhere you technically aren't knock out if the game yet, you'd be able to use what units you have left until you either go inactive (in which case they will disappear at next day change) or you lose all your units and haven't gotten any land back.

As long as you still have units, you can keep playing and try to conquer new land, but of course, money and resources disappear (you can not store them anywhere ).
And also, units are no longer automatically repaired on the day change.
If then the player becomes inactive, the Ki takes over, and without provinces all remaining units disappear and that's
the final out.

I lost all of my land but still had 2 infantry an artillery gun a militia a cruiser and a sub but it removed all my troops

Indeed, that is intended. If you've lost all your territory than you are entirely conquered and you lose the game. Your remaining units are deleted from the game. Why? Because in the past defeated players took their army at sea and kept trolling their opponent and it was just really irritation. Some players are just bad with losing. Luckily now we have this feature.