I have bought a Waveshare 7'' LCD (C) (https://www.waveshare.com/7inch-HDMI-LCD-C.htm) and it seems to work correctly on Raspberry PI 3B+ following the instructions on the site (it doesn't require specific drivers, just some parameters to add to
The problem I have is that it seems interfering with embedded Wifi card on Raspberry Pi and in particular with hostapd process.
I installed latest Raspian stretch (4.14.79) and Hostapd 2.4. If I keep the touchscreen USB cable plugged hostapd doesn't work well (wifi is not visible at all or it's visible but I can't connect). There is no error in the hostapd logs / kernel messages. If I unplug the screen access point works perfectly.
Do you have any idea where should I start to check to solve this issue?
P.S.: it's not a power issue since I'm using a 5V 4A PSU and I've checked that the current absorption by the screen is minimal (0.3 A).