I have problems with adjusting front shifting on my MTB so I suspect something is wrong elsewhere.
This is a 27.5" Merida Big Nine 100 XC MTB. Its chainset has been replaced with a Shimano FC-MT101 by its previous owner. Original chainset is SR Suntour XCM 40-30-22 CG (BSA) according to 99spokes.com. Bottom bracket shell is 72mm wide but I don't know the model of the bottom bracket so I don't know its width.
Do you think the space between the frame and chainring is too wide? It's about 1 cm. I suspect that's why I can't shift from smallest chain ring to the middle without tightening the shifting cable too much via the adjuster barrel on the shifter.
However the front derailleur's chain line compatibility is 50mm. So the answer is they are incompatible I guess.