I know 4 ft doesn't seem very far but in my case this is the maximum distance in order to have a reliable connection to my H9s. Surprisingly, I also found that orientation of the H9 also affect the communications with the dongle.
Because of that, I bought an USB extension cable and put my bluetooth dongle about 2 foot from my H9s this way. I strongly suggest that you try doing the same and see if connections are better this way. USB extension are cheap, you could also buy one with a base.