Turns out that the glitch happens at random.
I attached the console with RF cable and the glitch didn't appear so i connected the snes back with composite cable and for my surprise the glitch was gone, then i decided to turn the system off and turn on again, removing and inserting the sd2snes again and the glitch did come back, turned the console off and powered it on again and the glitch didn't appear...
I don't know what is happening but i assume that it has to be an issue that ikari_01 should check because it might be a bug in this specific version of sd2snes firmware, currently 0.1.7e.
What's your SNES's serial number (if you can't open it up)? I'm interested to see if this is another 1CHIP bug or not. I'll continue doing testing on my end, but I need to know if I should test on my Mini or one of my 3CHIPs.
Also which video output you use does not matter, as they are all generated from the same RGB signal coming off of PPU2. Just use the highest quality you can (RGB preferred, or S-Video if your TV doesn't have RGB).
And check the hash of the ROM you're using to make sure it's a good dump. It should match one of these:
https://superfamicom.org/info/super-mario-worldAnd be sure you are using the correct region ROM for your console (for PAL-M, you want to use NTSC ROMs, as the console operates at the same 60.098814Hz as an NTSC SNES, just with a different color clock).