Got another situation involving a DL/WS codeshare and looking for any suggestions. In my previous scenario, numerous ones of you mentioned that Delta won't book a ticket with more than 3 segments. This one is not more than 3 segments but still won't work.

Goal; YQU-YEG-MSP-ICT Mar 4
As shown by the following overlapping itineraries it should be available on one ticket
YQU-YEG-MSP is available on Westjet.com for $255.21 (econo)
YEG-MSP-ICT is available on Delta for $296 (main)

I did an ITAMatrix search and it shows availability on Delta and Priceline but neither work when I try to book it.
https://bookwithmatrix.com/db209ac2b...ae65dc207b2b95

Any ideas beyond buying separate tickets?