1 - my current location tracking accuracy within 5 meters , so is it considered fine ?
2- sometimes for every refresh on the heatmap , the location of some devices are changing frequently in 5 meters shift although they are stationary ?
Location accuracy is dependent on your access point placements. Also how many AP's can see the client is a main factor on how MSE and Prime displays the client on the map. A minimum of 3 Access points with a signal of -72 at any given location was the requirement for I believe 5 meters. It's tough to get less than that unless you have done a calibration or maybe have more access points that can reference the client device.
Location tracking accuracy depends on Access point placement and the location of some devices are changing frequently in 5 meters shift although they are stationary because there might be some configuration issues in the AP.
The device location is likely changing due to insufficient AP count providing coverage. If you are sure you have enough access points and coverage to support location services then placement may be an issue.
Another item of note is the following:
Guidelines and Limitations
• Access points, clients, and tags must be selected in the Floor Settings menu of the Monitor > Site
MAPs page to appear on the map.
• Recommended calculations assume the need for consistently strong signals. In some cases, fewer
access points may be required than recommended.
• You must select the Location Services to ensure that the recommended access points provide the true
location of an element within 7 meters at least 90% of the time.
Have you selected a calibration model within Prime?
I would recommend that you follow the following doc for configuring and testing your location tracking:
I hope this helps