Weak bluetooth range, wifi 2.4Ghz with low range, replaced antennas

Hi!

I got an iPhone X from a friend, but this one has two problems:

The bluetooth only works with a range of about 50cm, and wifi 2.4Ghz is not available, except at very low range.

So I replaced the bluetooth antenna, but the problem is the same.

The replacement wifi antenna was damaged during reception, so I couldn't replace it.

Any idea where this bluetooth problem could come from?