<p>Does anybody if the Anycube Mega X comes with a nozzle for 1.75 mm filaments or is it 2.85 mm?
I saw online that it works with 1.75 mm filaments but the Cura settings given by the manufacturer had 2.85 mm.</p>
<p>I should mention that using a 1.75 mm filament works BUT my designs have clear under-extrusion, which is very likely caused by having 2.85 mm in the settings. So at this moment, I am trying to gauge whether to change the settings to 1.75 mm or buying 2.85 mm filaments (this only works if the Mega X comes with the appropriate nozzle).</p>

Reading all 49 pages of the manual was fruitless. I'm astonished that there is no reference to the filament diameter used in this printer.
From
3dJake's web site
comes a confirmation that the printer uses 1.75 mm filament.
It's not a matter of changing a nozzle to use 2.85 mm filament, as the entire filament path is based, in this printer, on the 1.75 mm specification.
To find 3Djake's site, I used "anycubic mega x filament diameter" as the search terms. Many other links appeared, confirming the 1.75 mm filament size.