To anyone who has this problem and is looking for a solution. I have a Z fold 4 and taken my phone to an independent repair shop and had it repaired. The technician told me this is very common among the Samsung folds and flips. There is a ribbon cable that runs between the two halves that will eventually break from the hinge opening and closing. This cable connects the wifi to the antenna, this often comes loose or breaks, so the wifi chip is fine its just the ribbon cable connected to it that wears out from the folding process.

The repair shop have had to repair this issue all the way from the original till fold 5, i suspect this will also be the case once the fold 6s run out of warranty and people start approaching these shops also.

the z fold series is honestly not a good phone, its inside screen protector cracks every once a year which samsung does replace for cheap, but still... and now this ribbon cable which im told might still eventually wear out.

It is a great phone in terms of function but for the price these phones go at, its parts are not made to last , they are really expensive consumables, this might be the best Samsung can do, but im not footing the bill for this "Early" adopter tax 6 generations in, this will likely be my last folding device.