One thing that can interfere with a scorpions eating is vibrations going through the tank from an external source. Aquariums nearby can sometimes cause this,as can speakers playing music,even a TV at high volume for long periods,maybe an old fridge,anything that vibrates the floorboards or walls may send vibrations through the enclosure via the desk or stand the scorpions are kept on. A scorpion gains a lot of it's information about what's moving around near it by sensing vibrations in the air and substrate,they cant detect and home in on the vibrations coming from the insect if there is a constant background vibration through their enclosure,it may know something is nearby,but not be able to sense whether it's a prey item or something to hide from.
As already stated,scorpions can go long periods without feeding,particularly if they can obtain moisture from other sources,so their may be nothing wrong at all,but it's worth checking imo.
Also,you could try feeding the scorp crickets or other food items using tongs,if it grabs the insect it will probably be in defence,but once it has it it may eat it. Use long tongs,don't get tagged!