TernioCX can only support SP Initiated SSO, not IdP initiated.
If you are logging into the app and get a notice that your credentials are not valid, and there's no redirect to your SSO provider, then you are probably using IdP initiated SSO.
One option is to change the Ternio users only to SP SSO and keep the others on iDP. We have customers who have done this successfully.
A couple of things we will want to check. Are you able to login to the contact center directly using the same username and password you are using on the Ternio mobile app? Ternio uses your contact center login information to authenticate the user ...
OKTA needs to be turned off while submitting credentials for registering for the TernioCX mobile app. Turning this off allows everything to process perfectly and then it can be turned back on once the registration was successful.
When signing in, make sure you're entering a complete phone number. I also want to check with you and see if you are logged in to any other accounts using the same phone number you are trying to use with the Ternio as that can cause the spinning ...