Bad WiFi reception is a known issue from long time ago. Earlier threads like
this, for example ....
So, I think lot of Pumpkin owners have problems with this, but Pumpkin not the only one .... Another fact, that Pumkin is just a reseller company.
If You can post a picture, from your's HU back ..... - it could be much easier to define the manufacturer of HU. Usually, it is an easiest way, becouse each manufacturer use another type of MCU board with back sockets-line, and other shape of back plate ...
I have 3 pcs KLD (Klyde) unit, but I also having problems with the wifi reception, independently to use the stock-ROM, or Malaysk version. I think, the only way to do a much better WiFi, if I soldering a bigger WiFi antenna onto my motherboards. The factory installed is too little, and placed inside of the HU metal box ..... - not a good combination.....