ERG mode single leg drills

I’m wondering what set-up people are running that gets them the ability to do ILT drills in ERG. For me, I typically have my P1 pedals control my Kickr, PowerMatch on, connected via ANT+ so I believe I am dual-side connected. But when I tried to do ILTs today in Goddard my cadence dropped out to zero which obviously sent me into death spiral. I tried to change to Resistance mode (after some struggle realizing the change had to be in my Kickr connection, not my P1s!), but cadence still dropped out and I couldn’t stay unclipped. For the remainder I stayed clipped in and tried to just turn off my non-working leg.

Is anyone running this same setup that has had success with single leg drills. Or does anyone have a different setup that they suggest I use? Thanks