No post in a long time, but just want to ad for anyone else having antenna problems, I want to share a link to a potentially useful cable (if you are in the UK), thanks to @Patrick1 for clarifying the type of connector. The cable pictured looks like a Female U.FL to Female U.FL (also known as a I-PEX MHF) . I am guessing the part number might be U.FL-2LP(V)-04N1-A-(35) though I think the length may be too long at 35 mm. Also just guessing here but it looks like there are two of these, attached to the center board. Either way I will give it a go and update you here.
Here’s a link to the cables I have purchased: https://uk.rs-online.com/web/p/coaxial-cable/1360902/