I would try the following:
1. Make sure Tableau Server is running on the Primary Domain with a Domain Service Run as Account from the same domain and the setup delegation and SPNs have been created successfully.
2. Double check nicknames of domains by running:
If the nicknames are not set correctly, the login will fail depending on how the user accounts are entered into Tableau Server as Tableau Server cannot find the domain controller responsible.
Amend by running:
tabcmd editdomain --id 2 --nickname "new-nickname"