My only real issue these days are my knee replacements. What a pain that is. If I see a body scanner I ask for it. It is faster.
Flying back home in Canada last Wednesday they asked me to take out my 7D2 with 100-400 II out of the bag and she asked of she could weigh it. I said sure and she just held it for a few seconds. That was a first. Once in a while they swab a bag for explosive compounds.
I only had one major issue about 10 years ago. I was travelling in Canada with a Think Tank Airport roller. The airlines have overhead bin weight restrictions. The guy working at check in recognized it was a camera bag and asked me to put in on the scale. It was overweight so I have to remove lenses in until it was under. I was putting them in my pockets and plastic bags.
After that I put them back in the bag. I get on the plane and the guy was a flight attendant as well. Couldn't get a break that day. That airline has since lifted those restrictions and the last time I chatted with them they said as long as you can get it up there by yourself. Don't bring gold lol. That is what she told me. I have not tested it yet.
I have flown a few American airlines that partner with Canadian ones when transferring and never had any issues.