If you are being asked for your pin repeatedly, then your watch is too loose and it thinks it is not on your wrist. Either turn wrist detection off, or tighten your watch. You should only be asked for your pin once a day, when you put the watch on, or more if you continually take off and put on the watch. You may be asked for the PIN again the first time you open Samsung pay for the day but, again, only once. Having a watch too loose will also skew your exercise metrics. Your watch should always be snug but not tight. There should be no room for movement., but you should be able to slip a folded up $ bill under it. If you are still continually being asked for your PIN after checking the tightness, try wiping the watch's cache partitiion.
