At yield stress you already have 0,2% plastic strain (definition of yield strength). Using this as zero plastic strain will give you a discontinuous stress-strain curve. It is not very clear in earlier versions of the BPVC, but in the newest version I think it is explicitly stated that you should use a cutoff value for plastic strain of 2e-5 (if i remember correctly). Hence the first point in your plasticity model should be 130MPa with 0 plastic strain.