Why does my computer randomly type, "++++++++...."?

[TaylorEdwards]

I recently purchased a custom laptop from Sony. I am having a problem when I open Word documents where my computer randomly types plus signs (e.g., "++++++++++++). I have checked that I am not touching the keys and the key does not seem to be stuck. This also happens in chats and search bars. It happens mainly after the computer comes out of sleep mode or is just turned on. I can't find anyone online who has this problem.