2020 x10 PR means you got 10 PRs (for different durations) compared to your 2020 season, not that you got a 10-second PR. If you click on it, it’ll show you a graph that compares the power curve for that workout to the power curve for your 2020 season, and you’ll be able to see where the lines cross.
Here’s one of mine:
and the graph it shows me if click on the 2020 BBS #1 link:
Red is the current workout, blue is the season. I got a 12-second PR, 13-second PR, 14-second PR, etc.