Did you configure in the Authentication on ISE that if the mab fails to continue the process ?
enable also https on the switch
and add it to the redirect-acl.
Also add in the ACL permit to your DNS servers additional to the DHCP server.
maybe it is IOS-L issue.
Normally you should be redirected to the ise hostname FQDN by default.
also make sure you have a DNS entry that can resolve this FQDN on the endpoint side.
I hope this helps
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