ReadyNas Ultra 2 buggy fan speed reading ?

note : Initially I ask this forum because I have looked few times and it always was half the speed between the 2 speed displayed.
This morning I spent more than one hour playing around and I now understand how it's "working" :
1) the langage used by Frontview is based on the langage used by the browser (for me it was a french Safari). Thanks to apple I changed the langage in 5 sec and reboot, so I confirm my that the text explained in Frontview under "system>language" is true : IT IS based on the browser's language.
And about the fan speed I noticed the same problem : the 2 readings where completely different, but not anymore with "half/double" relation.
2) I refreshed pages many times, recalibrated, etc and then I understood the pattern :
When connecting to the Frontview homepage the speed of the fan is read at this moment even i the mouse is not put on the green light to display the speed in the overlay menu. Then it's stored somehow. To refresh this reading I had to refresh completely the webpage (like F5)
3) the fan speed inside the frontview text page under the menu "Status>health" is read when the menu is clicked onto it.
4)Here is why the 2 speeds are different 90% of the time because they are not read at the same moment. And apparently the fan speed reading varies a lot for an unknown reason. I believe waiting for 10 sec helps displaying the real fan speed (to stabilized)
The solution to obtain the same speed is, when logged in frontview is to display very fast the menu "Status>health" (the refresh is like avery few seconds).



conclusion :
Sorry to have bothered you all, but now I am confident about the usual fan speed I am having, therefore I am ready 'upgrade' to R6 when I'll catch enough hard drive space to backup all files.