I'm getting a warning that my iPhone was a jailbroken device

Hi gobo60!

It looks like no one has responded to your question. Here are a couple things that might help others answer your question:

1 Where are you seeing this warning, and what actions were taken prior to seeing this warning?

2 Are there any troubleshooting steps that you've already tried?

Cheers!

It is a strange way of warning that the app you are trying to use has not been updated to work with iOS 14. We have seen several such warnings with banking apps. What app were you using when you got the warning? the App needs to be updated.