Ex-Dub Expedia

Hi everyone,
Just looking at booking a UC ex dub flight via Expedia, but once I select the return flight, it says the seats are no longer available?
This is for lax, sfo, cancun! Is this just a glitch or do I have to access Expedia another way?
Any experienced advise appreciated
Thanks!
Just looking at booking a UC ex dub flight via Expedia, but once I select the return flight, it says the seats are no longer available?
This is for lax, sfo, cancun! Is this just a glitch or do I have to access Expedia another way?
Any experienced advise appreciated

Thanks!