I just tried to reserve the hotel and it said it's not available the night of the 18th. Huh? 19th to 26th is OK.I’m confirmed 7/18-25...
It seems that the reservation site is making some nights' availability contingent on the total length of stay... I'm not sure I understand the algorithm or the rationale. But the IAD is looking into it.
Cheers, -Benson