Fixed REG90 cannot connect wifi calling

whatthe??

    Have seen little for repairing this error code. New Samsung Galaxy S9 on T-Mobile network. Wi-Fi calling would not enable came back with code either reg90 or reg99.

    After much research, came to conclusion that it was sim problem. I went into settings apps  shows list of app installed. Find sim tool kit. Click on icon then storage. Clear cache then app data. Reboot. Problem was fixed. Hope this helps someone.

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