5D3 - Sticky AE Lock Button

Hey everyone, I had my 5D3 out in the cold weather (-2c) for the first time today. When I got back home I noticed the AE Lock button seems to be "sticking". If I press it down repeatedly it seems to sort of fix itself. But after awhile it will start to stick again. I use BBF so it's kind of annoying. Has anyone else had a problem like this? I'm not sure if it's to do with the cold weather or not...

Anyone?

Even in cold weather, if it is dry, it shouldn't stick. Stickiness seems to indicate that either the button itself is faulty or there is something that has gotten in there. Either way, it's likely a trip to Canon to fix but if it's a bad button, it should be warranty work (assuming you're still within the warranty period)