I think that may be symptom of the problem more than cause.

I had problems with the system not sending me the OTP login when I tried to book or edit bookings for a while. I even sent them emails about it, with no reply. I suspect they broke something internally and were either not sending emails, or sending mails that even Earthlink rejected connections from (I checked and was always receiving from Google and also my own MTA, as well as many others) so nobody could get through the login to book for a couple weeks. OTP with no login alternative (and not even text passcode alternative) was a really bad idea when they redid their system.

I checked again after seeing the posts about cheap parking and it's sending me the OTP again.