Can't send files over XMPP

I quit skype recently due to it being extreme shait.
I migrated to the XMPP protocol first via Pidgin and later moved to Jitsi.
I can have perfect VoIP calls and remote desktop sessions over XMPP,
but file sharing is extremely slow and connection keeps falling apart.
Basically I can’t send a file larger than 10kb.

I have the same problem with both Jitsi and Pidgin and my friends also have the same problem. We are all using the same XMPP server so it could be that, but it could be XMPP itself.

Can’t believe I can’t send files over XMPP though.

Any ideas?