We were allowed to wear our wetsuit during our pool swim for PADI OW cert.
Did you wear any weight with the wetsuit? If not your instructor violated PADI standards, which do not allow you to wear a wetsuit for your waterskills assessment unless you're weighted to offset the suit's buoyancy.
Per PADI instructor manual: "If conditions warrant, students may wear an exposure suit as long as they are weighted for neutral buoyancy."
Otherwise, you're using the suit as a flotation/swim aid... which is not permitted.