Can't move second/end loop point in piano roll

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Basically what the title says haha, I can't move second/end loop point in piano roll. I don't really know what to do, I've tried everything...

But yeah, if someone knows, please help lol. Something important to know is that I use lmms on a mac, so please give me instructions for how to do it on a mac... if anyone helps... that is...


...

hELP
Nevermind, I figured it out! But now for some reason it's not repeating properly... maybe I should find a video tutorial or something lol
and one with advanced feature :)
https://www.youtube.com/watch?v=2cFm8wT2cOk