I have cloned a gene in pGEX6p2 with N-terminal GST, C-terminal Flag tag and expressed in E.Coli BL21 with 0.1 mM IPTG, 30degree celcius at OD600-0.5, induced for 3 hours. After GST tag purification with GSH beads, I cleaved my protein with precision cleavage at 4 degree Celsius for more than 16 hours. I loaded protein samples before and after cleavage and ran SDS-PAGE. CBB staining showed protein after cleavage is higher than the GST tagged protein. How is it possible? I am beginner in this field. Hope will get some insight from the experienced people. Thank you

Note: MW of my GST tagged protein is 65kda, and the band I am getting after cleavage is about 70kda.