Immediate resignation after 6 months

This was my first job where I worked in a BPO, was still on probation, and did not render. Previous employer accepted this, was already given my last pay and 13th month pay. Now 6 months later, I am accepted as a staff nurse and did not include my experience in the BPO company since it isn’t considered a clinical experience. Pre-employment requirements include the COE and the BIR form 2316. I’ve contacted my previous employer and was told that they can give me the BIR form 2316, but not the COE since I did not render. Will this be an issue to my current employer?