How can I reset my WiFi password?

My iPhone 13 Pro Max is unable to connect to my home internet after a recent software update. My WiFi password is 6 characters (always has been) but my phone is requiring 8 characters all of a sudden. The “join” is greyed out until I add additional digits.

Verizon couldn’t help me.

Any suggestions, other than creating a new password for my WiFi (which means all of my other connected devices will no longer connect)?

HELP!

[Re-Titled by Moderator]