Well, this seems to work for me. Hopefully it will work for you. I too get frustrated when I can no longer pull up the console. It typically happens to me when I am in the UI and get attacked. It kicks me out of the UI and I can no longer get in until I die.

I tried those console cheat commands with no luck.

The way I am able to get the Left Shift - Right Mouse click to open the UI was to take out my gun, aim it at an wild dino and to Left Shift - Middle Mouse button. There's a short pause in my gameplay and then I can open the UI

I don't know what that is supposed to trigger in ACM but it lets me open up the UI aftertwards. I hope it works for you guys.