LUKS drive password correct but not working

I have a LUKS encrypted drive that I keep all my work files on because they contain sensitive information. The password was generated by Bitwarden and is kept in it. Bitwarden shows that it has not been changed since the original creation (only a few weeks old) so I know that I did not accidentally change it. It has worked every single day, including yesterday. But today I pasted the password in, and got the error message that the password is not correct. I know for absolute fact that it is correct, so why might it not be working? The only thing I can think of is that yesterday when I was finishing work I don't remember whether I dismounted the drive before shutting down. And the shutdown went weird; instead of shutting down the screen went blank with a plain text message that something had dismounted. I didn't think anything of it and held the power button until it shut the rest of the way off and moved on.

I have tried typing it in manually, pasting it in (which is how I've always done it before anyway), remounting the drive, and rebooting the whole computer. Nothing makes any difference. While it is not necessarily life-or-death to get these back, it would still be quite bad to lose them. Honestly, a brute-force attack would probably be faster than going back through years of emails to re-assemble it all. But I don't have the know-how so if it's possible to just get the drive working that would be great.