It changed sometime last year, maybe 6 months ago? Yes, the new log-in is "your employee ID #"@ups.com, IIRC you should still be able to use your existing password, but be prepared to come up with a new one. You may have to change it immediately, or in the near future. Including upper & lower case letters, numbers, and a character.
Try some of the tips on this thread:
UPSERS.COM impossible to log in | UPS Discussions, or this:
Sign on | UPS Discussions
You may have to login from a computer at least once, first, not mobile phone.