Can confirm. I'm DMG and I'm actually bad at the game. Very bad.Just play a casual game or two and check competitive mode again. I have also alluded somewhere earlier in this thread that accounts created in another country via VPN or has a purchase tied to another country does have trouble with new CSGO accounts. It is like the system knows that you bypassed something. This usually corrects when you do get a local lobby.
Just know, say you are indeed a SUP, your skillset should auto rank you by competitive win 10 to DMG or Eagle. This game does grant you with a hidden rank, by game 5-6 it will get tough or Valve may even insert you into untrusted territory to test you.
SUP by solo queuing, GG.
I believe my true rank is LEM, but the game in the condition it is in is rather easier at the higher levels than it used to be. 4 years ago you had to be REALLY GOOD to be DMG, now it is a glorified blue rank.