Hi. I'm in the same boat as you and have just this minute spoken with UKVI. It all depends when you started the course at university and if you had continuous employment throughout the course.
The regulations were changed in 2011 when it became mandatory for EU nationals studying in the UK to hold CSI (if the course started before that you were fine for the whole duration of the course).
If you finished the course after the new regulation came into effect the time of study between the new regulation coming into effect and you finishing the course is lost with regards to the PR application.
For example, I myself started the course in February 2010 and finished in February 2013. This meant that I did not need the CSI but the time up to February 2013 does not count towards the PR-5-year-period.
However, the advisor said to me that there is no need for CSI if the student continues with any regular employment throughout the course (at least 1 day per months paying NI contributions). The fact that the course was/is full-time and the work is only 1 day per week does not matter (I asked this question because I myself are going to return to uni in September this year for a 2-year-course).
I hope the above helps, sorry for it not being good news
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