SaaS owners who use SSO. How many people reach out forgetting they signed up via SSO?

Our SSO is giving us a huge support drain, and also contributing to churn. On average we have at least 3 people reach out daily saying they can't get access to their account. Every single time it's because they created their account via SSO and are trying to login via email and password. This can cause users to churn because if we don't get back to them quickly, they get very angry that they are locked out of their account.

I'm considering removing SSO completely. However, SSO seems to be extremely common in the SaaS world. I'm curious how others handle this problem that seems like it would be very common.