Disable CTRL SHIFT Arrow

In a non-RDM app, like Notepad you can type a sentence and then select text using keyboard commands, like holding CTRL SHIFT and pressing the left arrow 10 times to select the last 10 words. In an RDM RDP session, I can sometimes do that... other times RDM interprets that CTRL SHIFT Left as I want to move to the next tab to the left. Is there a way I can disable RDM from capturing that command? I'd rather select text than move tabs with my keyboard.

Thanks!