via the ARRL: LoTW Password Checking Change Causes Problems for Some Users

An upgrade to the password-checking mechanism that authenticates Logbook of The World (LoTW) users has caused log-in problems for some clients. Under the system in place prior to approximately 2300 UTC on September 19, the LoTW log-in system ignored the case of any characters in a password when checking for a match, storing them all as lower-case. The new system is case sensitive, however. While passwords once were randomly generated, the ARRL IT staff recently implemented a new LoTW password mechanism that lets users choose their own passwords. Under this new system, when users first log in, their passwords are encrypted.
via American Radio Relay League | Ham Radio Association and Resources