So I found a solution to this if you don't want it appearing. Opening avast antivirus on your computer, selecting the top right menu bar, then select settings, after that select protection, select core shields, then scroll down to "configure shield settings". after that select web shield and then disable the enabled "Enable QUIC/HTTP3 scanning". then close avast, and restart your browser, the "managed by your organisation should disappear as that is what i did to make it disappear from my browser. sadly this does remove a minor protection from your browser but gives you extra privacy.