Stress reset at start of the year?

When viewing my stress progression chart it appears to reset at new years. Is this just a problem with the graph or would it be affecting some of the calculations? I didn’t make and reduction in my workout intensity or frequency. Capture

This is an error. To correct, you can perform a full Progression Recalculation (see FAQ) or an easy hack is to add a manual activity in the past (even with just 1 XSS). This will force work, strain and XPMC info to be recalculated.