Help regarding ground buzz

Background:
So I just bought an audio interface recently so that I could record my guitar
Following is my setup and observations:
Guitar (Dean ML) is connected to a multi effects processor (Zoom G1Xon) and its output then goes to the Audio Interface (Scarlett solo 3rd gen) ultimately connected to Laptop.
When I connect my laptop to external power source (AC) there is a continious buzzing.

Situations when the buzzing stops:
1)Turning the tone dial on guitar to zero or,
2)Running the laptop on battery and disconnecting from wall socket or,
3)Touching the metal parts like the Audio interface or the guitar cable connected or,

4) Switching to some cleaner tones with lot of reverb and no distortion/gain.



I tried reading this post(https://www.prosoundweb.com/eliminating-troublesome-hum-buzz-created-by-electric-guitars/) but couldn't understand all the technical stuff and got confused with the following:
Whether the issue is with my guitar's ground cable or is it due to connecting two things at a time (The processor and Audio interface)
There are no good guitar shops where I stay so getting my guitar repaired will cost me hell lot of time, travelling and money.

Any help is appreciated in Advance