I'm asking this question for my wife. She has many years in the saddle and is a strong biker. She rides two different bikes. Her outdoor bike is an Orbea road bike that she hasn't been on much in the last couple years. She rides the trainer indoor on a QR tri-bike. So over the last couple years she has put more time in on the tri-bike. She has been wearing the same two pair of bike shorts for the last 7 years and they are on their last leg.
Last week we actually went for a ride together outside and she did 30 miles with plenty of climbing without any problems. This week we were going to ride a little bit longer so she went and bought a new pair of shorts, Assos with some compression. We get out on the ride and her feet an lower legs start falling asleep. This makes the ride miserable for her so she cuts the ride short. This morning she got on the trainer with the same shorts and starts having the same problem. She got off the bike and changed into her old shorts and she felt better.
Have any of you ladies had this problem? Any suggestions? I've never heard of anything like this happening.

Thanks