Speed throttled to 10 MPH

My wife and I had a meet up Saturday 5/2. We have done this several times. At different points in the ride we were throttled down to 10 mph, could not go any faster no matter the effort. If we were going -4% downhill with both of us over 2.4 wkg…it was at 10 miles an hour. At other points in the ride, things were normal but on some climbs our speed was up over 20 mph for a 7% grade. For us, 20 mph uphill is not happening in real life or ever before in Zwift. We rode 63 miles and the pace and time were pretty accurate in the overall scope. Cyclops Magnus and M2 trainers, ant+ dongle, zwift running on laptops and cell phones companion app. Course was figure 8. As an example, we started off at 10 mph, could not go faster. when we hit the board walk(?) then speed was regular, we could go over 10 mph…but then it changed back, like immediately after the KOM, going downhill we could not go over 10 mph no matter what we tried.