Just looked up the schedule for YYZ - ORD - was looking for May 3 and 4th. United site claims that the only flight they have is at 7am on either day. Checked the app as well, and clicked on the tab for all days that week when doing the search, and got the same thing - just 7am. There should be about 7 or 8 UA/UAX nonstops a day, plus about 6 or 7 UA codeshares operated by AC.

Also, on an unrelated note - and perhaps this could use its own thread or go in the new website thread, noticed when doing an award search that the "purchase this reservation for $XXX" doesn't seem to show up any longer when part of the reservation is on UA-metal - seems like the Economy Plus essentials buy up offer page seems to replace it. Did a all international, so all partner award search, and the purchase banner did come up. So not sure if this is unintended not to have the purchase banner come up. But was definitely helpful in some situations, so a bit of a bummer its missing.