I had my R5 lock up for about the fifth time now, but mine sounds slightly different than what others are experiencing. In my case, the camera just won't let me take a photo. Then after a second or two, the shutter button works again. I don't have to turn off the camera/remove the battery, or anything like that. It's not focus release (I'm on AI Servo and I have the One Shot as shutter release anyway, plus I'm in focus). I'm using BBAF, with AF-ON serving as the AF button. It's not a buffer issue...today it froze after about 2-3 frames in a sequence, but all the other times, it wouldn't fire the first shots of the sequence. Starting to get a little frustrating, because I've missed the subject the past two times it's happened. I feel like it's a software thing, so I don't want to send it in and have the same issue occur...plus it's my only body at the moment, so I can't be without it.