I now see that bar #3 in Cubase has 6 beats. Was it like that before the copy? (Create a Time Signature track in the Cubase Project, to see any changes)
Thanks Vic. You’re right. When I created the Time Signature Track, it showed 6/4 time at bar 3. Weird.
Nevertheless, when I changed it back to 4/4 and copied and pasted the original loop, it still was only 2 bars long.
What happens if you try to drag the bottom-right corner of the original Part (to extend it)? Does the 3rd bar actually contain anything? (try looking in the List Editor).
When I drag the part, there’s nothing else there.
(or maybe there is some hidden data in the > first > bar, and we are seeing only bars #2 and #3?)
Without actually having Superior Drummer here, it is a bit difficult to second guess what is going on there > 
That’s it. The List Editor shows only 2 bars…

…while the channel part Part shows 3 bars. Why is that?

There is no hidden data that I can find. There’s no part underneath the Superior loop part. Where else would I look?
Thanks again for your help. 