Hello,
For some time I have been using a QRP Labs U3S for WSPR. Only on 20 meters do my decodes from other stations reflect wrong Grid and power levels randomly. I monitor my own transmissions with a local copy of WSJT-X and never see this happen. I am just trying to figure what is causing this. I have attached a screenshot to help explain what is happening. I am running 1 watts and the grid square being sent is EN81 but in the capture you can see what is happening. Any help would be greatly appreciated.

Thank You,
Larry