It is nearly impossible to make seamless loops at a reasonable pace in Studio One.
There is no snap to zero crossing, so you have to zoom in all the way and find one yourself if you want a loop without a terrible click.
And even when you zoom fully in both axes, some spots that appear as zero crossings aren't even zero crossings because Studio One's waveform resolution is terrible. So, even if you do everything correctly, you might still end up with a ******* click, and you have to repeat the process all over again.
I should note I am trying to do this right now for a project I am working on, and what should have taken me ten seconds by printing through a loop point, making a cut there, and relative snap dragging back to the beginning and creating a crossfade in the middle has now eaten about an hour because none off the zero crossings Studio One is "showing" me are real, and I'm still not done. BACK TO PROTOOLS IT IS THEN! Will literally take me ten seconds to make this edit in there.