rejected from places with high acceptance rates but accepted at places with low acceptance rates?

Applying to College
14

UCR is generally considered easier to get into:
http://talk.collegeconfidential.com/university-california-general/2127392-faq-uc-historical-frosh-admit-rates-by-hs-gpa-2018.html

So getting into UCR but not UCD is not that surprising.