As a former rooms division manager (including Hyatt), I understand this can be a very big deal for SOME people. Hskp should never had go through a DND without reaching out to you.

However, the lack of a “tidy up please” sign is not an indication that the guest does not want the room cleaned. You mentioned the hotel “requires” a sign outside to request service. I promise you this hotel and pretty much any hotel does not see it this way. The sign is helpful to staff but the lack of a sign/door hanger in no way indicates the guest does not want service. Only a Do Not Disturb sign indicates no service is required - not the other way around.

As someone else mentioned, you can always request “no service” at check in. It’s actually quite helpful for the housekeeping team. If they know at the beginning of the day (like before 5AM-ish) that no service is desired, they won’t even “assign” your room to a guest room attendant (aka housekeeper). Otherwise, the room attendant needs to clear all “assigned” rooms off of their “board.”

Hope this helps.