Trouble connecting to Arduino mega 2560?

Hello, I was working on a project with an Arduino Uno, but recently decided to switch to an Arduino mega. I just got the mega, and I'm trying to set it up right now with my computer. I plugged it in and it installed the drivers successfully. I restarted the Arduino software and now am trying to select the board/COM port under tools. I can see the option for Arduino mega/Arduino mega 2560 under boards, and COM4 under ports (my Arduino Uno is COM3). However, when I click these options, they don't stay selected. I click Arduino mega under boards, but Arduino Uno stays selected. I click COM4, but no port gets selected. Then, when I try to upload to the board, it says there's a problem, and when I try to compile code that only works on the mega (like Serial1), I get an error.

So what's up? Is there some kind of trick to selecting a new Arduino?

Okay, I actually solved the problem. Turns out it was a problem with my mouse ha ha. Not sure how to delete the post though so I’ll just post this to make it clear