I had faced a situation where after changing TCA CP password and updated in compute CP as well started showing error while creating workload cluster.So here is the scenario- Using TCA 2.1 Customer update TCA CP user password. This new password was validated by login into Compute VC. I've update the password under TCP CP:9443 and within TCA UI under Virtual Infrastructure and choose option for the sync. From this moment - when I'm trying to create new Workload cluster - this operation is failing with error: Unable to create k8s cluster with error could not create VC client: ServerFaultCode: Cannot complete login due to an incorrect user name or password
Resolution-
Password must be the same of MGMT domain. It looks like MGMT VC access with this user/pass combination was not working.