Confirm and Confirm/Allocate are not going through. Resource Plan logs say it did but 0 hours were confirmed/allocated. Resource Plan state did not update.
The issue is that the User specified did not have a valid Schedule associated with their User Profile.
There were no Schedule Entries to define working hours.
If you were to change the Schedule to one with Schedule Entries or remove it from the User Profile, then the Confirm and Confirm/Allocate buttons will function.
By removing the Schedule from the user then the default "Resource Management Schedule" will get utilized.
To update the User's Schedule, follow the steps below.
1. Navigate to Resource > Resources > Users
2. In the "Name" column search for the user and go to the record (you should be in the Resource Manager view)
3. Remove the value in the Schedule field
4. Save the record