slip through
phrasal verbwithslipverbuk/slɪp/us-pp-
[IorT]
tofailto benoticed,resultinginproblems:
It is tooeasyforproblemstoslipthrough because there is noclearregulatorat thetop.
Although thecostof themedicationswassupposedto becoveredbyinsurance, thingsslippedthrough thecracksa lot.