This behaviour described may be due to having GL1DE enabled on your receiver. The default configuration sets pdpmode relative auto, which is the GL1DE mode optimized for on-tractor pass-to-pass accuracy. There could be two reasons for this kind of behavior: 1) GLIDE is forced to stay in DYNAMIC mode (if it is not set to default AUTO). 2) GLIDE is set to AUTO mode. In this case, it will detect the stationary mode, however, it may take some time to be stationary. GLIDE uses double differenced phase observations to estimate velocity. If the velocity is below a certain threshold, the mode will automatically switch to stationary. GLIDE is intended for applications with open sky conditions. In urban canyon environments (e.g. downtown high rises) where signal multipath is present, the algorithm might receive corrupted measurements that are still used within the solution and the zero velocity detector may not work. GLIDE first propagates its position based on its last available velocity estimate and after some time, it indicates "not-available-solution", if there are insufficient satellites tracked. GLIDE is mainly intended for open sky applications and not within an urban canyon.