I have Bitdefender AV Free installed, and it is blocking NOVNC on browsers

I have several instruments that allow remote control via web browser using NOVNC. Using any browser I type in a local IP and I am supposed to see the instrument screen. This was working fine a couple of months ago, but now I get a blank screen instead of the real time image of the instrument screen. I have disabled all Bitdefender functionalities as well as added the IP as an exception, to no avail. If I uninstall BD AV Free, things get back to normal, otherwise it is impossible to use remote control via NOVNC on web browsers. BTW, instruments under control are Siglent Oscilloscopes.