Combo cheers when activated and highlighted instantly spends bits on mobile without any pompt. Before they are activated you need to tap it and then confirm by tapping the emote you want. I did normal cheers with bits and it triggered combos on mobile. I tapped the highlighted combo that normally opens up options but it just instantly spends bits. I tapped it twice thinking why is it not opening, but realized after I had less bits than I did before it was triggered because I didnt know with it highlighted it instantly spends ur bits. Its in a spot next to your text bar so when activated you can easily tap your phone on accident and instantly be charged bits.

Make a combo streak highlighted still, but make it so you have to open the list of cheer emores with combos, not just a click on the main screen instant bit charge.

I assume a lot of people spend bits learning this the hard way.