Steve, you have the loop option in ST1 activated so first deactivate that.
1-if your keyboard plays that drum loop over and over just hit record in ST1 and record as many measures as you like. You may have to trim the start and end of your recording so it starts on measure 1 beat one and ends when you like.
2-if your keyboard does not play the loop over and over then record one measure in ST1. Trim your recording to one measure as ST1 will record prior to and past your keyboard loop. Make sure it is a full one measure. Click on that measure and hit D (duplicate) as many times as you need.

I hope this helps.

Whenever I get something stuck in the back of my throat, I dislodge it by drinking a beer.
It's called the Heineken Maneuver.

64 bit Win 10 Pro, the latest BiaB/RB, Roland Octa-Capture audio interface, a ton of software/hardware