Dear Suttichai W,
Good day!! Wish you a happy new year~
I understand your concern and to my knowledge, the behavior you are encountering is not an expected because I have tested the behaviour at my end after updating the Microsoft Forms sync to new sync where I am able view the latest responses in the responses Excel workbook without any error and no issue with the other users accounts as well.
Since you have mentioned the problem happen with multiple users in your organization, I have checked service health dashboard at the Microsoft end, where there is no related incident found.
In this situation, I believe the problem should be investigated by the related development team where they can collected the related logs while reproducing the problem and perform the further investigation.
So, I request you raise a new service request from the Microsoft 365 admin center, where the related team can connected with you via preferred contact method and check the issue further.
Reference: Get support - Microsoft 365 admin | Microsoft Learn
Note: Please accept our sincere apologies for redirecting you to related development support team because the moderators in this community are limited with the resource for further investigation and to get a quick resolution to your problem, we requested it.
Appreciate your patience and understanding. Have a great day!!
Best Regards,
Sophia