Debian 11 Proxy not working with mate but not mate

Hi Linux forum, since I'm thinking of switching to Linux as a daily OS I decided to use my university lab to make some test and I created several virtual machine to see how the different taste of Linux feels like.

I encountered the following problem : Our university requires a proxy for web browsing, no problemo I will just copy the settings of the host machine on the vm and that should work.It worked for the vm with the Debian OS and mate desktop environment but it didn't for the vm with Debian OS and KDE as a DE.

I tried all the options :

• Use proxy auto configuration URL:
• Use system proxy configuration:
• Use manually specified proxy configuration:

I've tried to check the "use this proxy server for all protocols" options but still, no success.
I have verified that the vm has an ip address received from the DHCP, I have verified that it is capable of pinging machine outside of the university network.

Still no web browsing for KDE, Any tips on how to configure the proxy settings ?
Thanks for reading.