That sounds like my experience with Commscope's CAT3 4 pair cable.
Old Systimax 4 pair CAT3 had traditional insulation.
Today, Commscope's CAT3 4 pair is CAT5 that didn't meet specs. Commscope labels and sells the cable as CAT3. The insulation is translucent and can be difficult to, correctly, identify the pairs.
