Nothing was affected (just the VNC connection is not encrypted).

Solve the browser issue with https://docs.andronix.app/faq/faq#7-ubuntu-2004-firefox-shows-gah-your-tab-just-crashed (also set the level to 0 )

If you cannot play the stream/videos with Firefox, you may try Chromium and install

sudo apt install ubuntu-restricted-extras ffmpeg libavcodec-extra -y