Pyramid interval session issue – watch stopped tracking intervals correctly

[mauog]

I set up an interval workout that started with a warm-up, followed by pyramid intervals based on time: 1 min fast / 1 min recovery, 2 fast / 2 recovery, up to 4, and then back down to 1. The workout ended with a cool-down.
The watch correctly handled the interval changes up to the 3-minute group, but then it stopped signaling the transitions. In the activity report, from the 4-minute interval onward, everything is merged into a single block.
Has anyone else experienced the same issue?

Thanks