Hi Igov, to me it is amazing to have one of the co-founders reply to a technical forum lead, that is the beauty of Emlid.
I have been using my new RS2+ for last 4 months. It has been a joy to use it. However, I had similar issue two weeks ago as the one Alessio had. I took a check shot on a mark that I established and checked many times, the vertical error was 70-110mm, while the horizontal was as good. It only came back after I switched off the unit and turned it back on. Then the same issue came back 2-3 times.
I have also found another issue, that the coordinates (horizontal) shift 20-40mm if I rotate the unit or face the other way. I was using new sharp straight carbonfibre GNSS pole.