Can i ask what companies you interviewed at or what industries they were in? Also what type of questions did they ask? i.e did they test you on your knowledge of designing for manufacturability - (some schools do not touch on this at all)
Lack of experience can mean many things even for recent graduates (beyond professional work) and sometimes be things that your school did not teach / or the student did not take the time to learn…
pm me and im happy to talk via phone - and ask some probing questions to better help provide you with insight.