prb not come from ur plastic card : becoz u encode only the track 2 and not encode any chip info
Prb is the Pos are equiped with EMV ( Europay Visa Mastercard ) system and pos detect something wrong . (POS know these track need be read by the chip ... so he ask chip )
thats the prb when u use 201 from ur country .( 201 uk in uk ... ) if u want use 201 choose another country of 201 in this case for international transaction he could accept payment only by track 2 reading .