So, I'm not too familiar with key generation, but do you know why your key contains underscores? Mine has slashes, and I can't find any information on why a key would have underscores instead. From the little research I did, I found this table which contains the characters that a key is made up of and I don't see an underscore. So, I'm wondering, would it be better to change the key itself instead of the code doing it for you?

This has been my first foray into key generation. When I wasn't able to connect to snowflake I tried creating my own JWT and failed at that so I just resorted to trying to debug where in your code it went wrong. That's where I discovered the fingerprint was "correct" but it had underscores instead of slashes.

If I find some time I will try running it from a different architecture and see if I have the same issue.