Well, I won't go so far as to say that I found the issue, but I have found that through some mysterious set of conditions somehow my laptop learned my mailbox p

Well, I won't go so far as to say that I found the issue, but I have found that through some mysterious set of conditions somehow my laptop learned my mailbox passphrase. I use lastpass, but lastpass doesn't have a record in the database with it (I would never intentionally have it save such a passphrase). I disable browser password saving on any system I use. I've only ever typed that passphrase on the protonmail website to decrypt my mailbox. This is very strange. If I tell lastpass to autofill the password on the mailbox decryption page, the password fails. But somehow it starts out filled in with the correct one. Honestly totally at a loss, but probably not an issue with ProtonMail and more likely some accidental thing I must have done to put it into memory. No clue what I did wrong.