The iPad and other mobile devices will have two antennas.One for the 3.5 band and another forth 5 band. It maybe that the 2.4 antenna has been disconnected or even broken. To fix it you would have to open it up.
This has been documented. Also, this kind of problem can relate to Bluetooth also.
Here is one of many references about iPad signal problems:
https://www.lifewire.com/troubleshooting-weak-wifi-signal-1994538However, the author failed to mention that fixing t he antenna should be considered.
See here:
https://www.pcmag.com/article2/0,2817,2362319,00.aspYou have to wade through the article to find they also meson the antenna.
A comment says it:
BigEli • 8 years ago
I bought a Wi-Fi Catcher 10 dBi Patch/Panel Laptop/Netbook Antenna for my new Ipad ........The internal antennas suck..... Hooked the Wi-Fi Catcher antenna up by any USB Adapter......Solved the problem for under $25.00 +12.00 for the Adapter...Brother, I pick up the Neighborhood over on the next street in Wi-Fi with this antenna.Ipad and a Wi-Fi catcher antenna is like Cake to a fat kid...
(I deleted the reference to another site.)This is not just an Apple issue. All mobile devices can suffer from a antenna disconnect. At close range it will work, but and any distances of more that a meter or two the signal will drop out.
In some cases the internal antenna has come loose. Easy fix, but yhou have to open up the case. Here is a YouTube guides:
https://www.youtube.com/watch?v=JZqUNlVg05Qhttps://www.youtube.com/watch?v=y-kmGcu2zMMI hope this is of some help for fellow iPad owners.