I'm doing the 10k program by coach greg on my fr 955. I'm starting with fast runs in the target pace. There are several 1 minute intervals in or above the target pace. It's really hard to hit the pace as the current pace measurement seems broken. The gauge during the intervals is jumping from one extreme to the other, although I'm not changing pace. I got a 33% for the training and this is frustrating. My GPS is on highest accuracy and 1s refresh rate. Sunny sky, no clouds, buildings or trees. Is this how it's supposed to be or does my watch has issues with GPS? (Fw 15.12 / GPS 2.47) Thank you!