DL IT is just terrible here and there isn't much more to learn there. Forcing an even reissue sounds like the right thing to do anyway, since it's a schedule change.

For what it's worth, 25-Apr-26 LGA DL550 X/ATL DL1472 EYW is a perfectly valid routing for a Companion Certificate and in fact uses the same fare as the nonstop. I also see several valid connections JFK-ATL-EYW on the same date.

edit: did you remember to search for two pax on Matrix? I forgot... LGA DL988 X/ATL DL2815 EYW works though, and is displayed on an original search by Delta too.


One of myriad issues DL could be having is that I am fairly sure there are still copies of the code somewhere enforcing an L or lower basis, as is required for Y or C+ certificate use - this would restrict options to I/L or lower, excluding I/K and I/Q. This lovingly clashes with another copy of the code which permits all I class but no Z class, because the permitted classes prior to realignment were A and I.

FWIW, I am finding original (new) searches with a Companion Certificate on the DL website to work correctly.