It sounds like the hotel lock does not recognize the key cards being used. There could be a few possible reasons for this issue:

1. The Lock’s Card Reader: There might be an issue with the lock’s card reader. If it’s not functioning correctly, it won’t read the information from the cards and, therefore, won’t unlock the door.
2. Card Programming: If the cards are not programmed correctly, the lock won’t recognize them. Make sure that the hotel key cards are programmed correctly for the lock.
3. Lock Memory: If the lock’s memory is full or there’s a glitch in the system, it may not accept any new entries.

As for troubleshooting, please try the following steps:

1. Try using different hotel key cards: This will help you identify whether the issue is with a particular card or the lock itself.
2. Reset the lock: Most locks have a reset procedure to clear their memory and reset their system. Refer to your lock’s manual for the correct procedure.
3. Reprogram the lock: After resetting, reprogram and try using the cards again.
4. Contact Support: If none of the above steps work, it’s best to contact the manufacturer’s customer support for more detailed assistance.

Remember, these are just general guidelines, as I don’t know the exact model of your lock. Always refer to your user manual for accurate information.