Workout Day 4 in 10-12 week program was glitchy.

I was doing the workout for week 3, day 4 and when I got to the part where the instructions indicate 5 x 1 minute at 103% of FTP, after I finished each 1 minute interval the tension level felt like it increased so hard that I couldn’t pedal.  This happened every time or 5 times.  I had to stop pedaling and wait for the mode to pause then the tension would lessen and I could resume to the 2 minute next segment.  What’s up?  Not sure what the issue could be.