When I mount my tablet in a metal holder that I made, it loses WiFi signal. Thank you in advance.

Metal will block signals, best advise would be buy a proper mount.

As AlanHD says metal will block and reflect radio signals. For this reason the nose cones of military and civilian aircraft are not made of metal, usually radar and other similar equipment is contained behind them. Either you have to invest in a commercial holder or make one in a suitable material. Any plastic including GRP, resin, honeycomb, but not carbon fiber.

Hi, sir. I would not recommend you use the metal holder. Can you use our app to build the wifi connection without this holder? Please keep us updated, thanks a lot.