Not trying to be skeptical.
27 XMR = around 400 USD. Pretty rare to exchange ask for some proof-of-fund with this amount cause is pretty low. Perhaps you could try to export every deposit you've made with Kucoin. Share in here, and other maybe can somehow track too for helping.
I guess these could somehow trigger some warning for the transaction from activity prohibited against their term & condition. Anyway, where did you do the freelance? In some freelancing website? If yes would be very nice to contact them for maybe a bit of help to verified all the payment you're receive are legitimate from the freelance. Hopefully they can accept those as proofs for the payment you're receive.
27 XMR is currently valued at 10,668.41 USD
CEXs often trigger automated AML reviews. The first step is never using a CEX to exchange crypto.