verified game files?

on the off chance:
some characters do not always work in some password software. Try resetting the password to something with a different kind of pattern to what you used last time, eg different punctuation marks or heavily leaning on upper/lower/number characters and only basic punctuation marks.

also, if you copied/pasted from a program with artificial stupidity, specifically but not limited to MS word, it can and will change the characters behind your back and then when you copy it, you have the wrong code, and you can't even visually see this.

Seen a lot of this happening on Reddit so I'm taking my post there as people here can only suggest potential spelling issues that have already been ruled out.

We copy pasted it already to rule out any mistakes and it just will not let me in. This is so stupid -_-

When this happens to me it's usually the capslock

I have had this, I created a text file and type the password in there and then copy and paste it in Valheim, (careful not to grab a space) that way you can check it is typed correctly, I think Valheim struggles a bit with special characters. 8 to 10 alpha numeric characters will be fine. Hope you get sorted.