of all people my mortgage servicer is the worst about this. Your login is valid on like 3 different top level domains and you get bounced between them when you sign in, eventually going from servicer.com to myservicer.com to servicer.otherthing.com! It's as though they were training you to not care about domain names.

Paying US taxes online is just as bad. The official way to pay tax balances with a debit card online is to use officialpayments[.]com. This is what the IRS advises you to use. Our industry is a clown factory.