[rudra]

i have a guess here. I faced similar issues and used commandline tools to detect if the browsers are managing the connections differently. I saw a couple of different udp connections for chrome on those tests. Didn't explore further after that. But later chanced upon QUIC.

Here is my guess...

May be chrome is using QUIC and your provider has less load or/and restriction on the UDP ports. Hence faster speed when using QUIC.

QUIC is a newer protocol over UDP that is working wonders for sites like youtube.

here you can read more, apart from wikipedia etc..

https://blog.chromium.org/2013/06/experi...c.html?m=1

https://brave.com/quic-in-the-wild/

as of now, FireFox lacks implementation (wikipedia).

Just a guess.

I am sure HR will inform us more on the probable causes.

EDIT.

I see that only commercial litespeed, google, go implementation and caddy have server implementation of QUIC.

So now it seems i dunno how to explain the time this site takes on firefox when you press submit.

another guess....is it the google adverts and services that this site uses that is causing this ? those use quic on chrome to load faster but not on ff ?

lol.

no idea

EDIT2:>

you could do a test yourself. Use chrome after disabling quic and compare with the performance when it was enabled.