I keep having this issue every time my phone updates ever since ISO 14. To fix the issue Go to Settings, select General and select Reset All Settings. It will not delete any information but will clear all usernames & passwords that automatically pop up on websites. But it doesn’t delete the usernames and passwords Saved to the phone. In settings I have also turned my automatic ISO Updates off until they fix this problem because it’s quite frustrating to have to reset all settings every time my phone updates. I hope this helps