I first experienced this, when my boat was about a year old! It is a 2014 TI Hull. It happens to be my Rear Starboard Aka, that was coming out. After it did it the first time, I made sure to have parachute cord aboard to lash the Aka to the Crossbar! When you have it lashed tight, when the Ama's are out, it merely slackens when you fold it in! I thought about this issue, and found out my "Fix" was actually done by some owners in Hawaii, they have called it a "Hardening" solution! To me, anyway, I feel we all need to do this fix!!! My issue occurred when I was in calm waters, I certainly would not ever want it to occur when the conditions were bad, and I was far from landfall! Not good!
So, as my Rubber Boot on the Xbar was deteriorating anyway......cracking all over, I ordered 4 new ones. I call it the boot, but is like an End Cap on the end of each xbar ( Crossbar ), that is screwed on top and bottom! You have to take the Xbar off, to actually replace them, then reinstall! I may do that eventually, but have the Boot already ordered, to do it when I get "Round Tuit" !
The only way I can see that the screws that hold the Spring Clip in can actually seize when taking them off, is because of Galvanic Corrosion which occurs when two dissimilar metals allow for it to corrode just enough for them to seize? They simply screw into Plastic Spring Clips, so it seizes on the contact area of the Stainless Screw, and the Aluminum Crossbar! Spray liberally with PB Blaster and let it sit for a couple of hours, or if they are really stubborn, just drill the heads off with a slightly larger drill bit! I took the Spring Clip out did try and expand it, and it broke way too easily! It is plastic that has a weird consistency like bubble gum that has hardened, and breaks! They should be Nylon, if anything?
Getting back to the real fix here folks, this is what I did, and it works like a charm. I believe this should be done this way at the factory, as it is much better, and cannot fail! As said, it has been dubbed " Hardening", and what it consists of is a Stainless Steel Double Wire Snapper Pin ( Identified as other things elsewhere, Hitch Pin, commonly )! Here is the P/N reference https://www.fastenal.com/products;jsessionid=2DC24603BC649C1B7B58EAC238CE0829.fcomjvm03?%20term=11104144&searchMode=
So, you take the pin part of this Snapper Pin, and find the closest Drill Bit size to it. You go to that Rubber End Cap, put the Aka in it's Xbar slot, make sure it is all the way in, and drill a hole Horizontally through the Xbar, through the Aka piece and through the other side of the end piece! It is that easy, and you never have to worry about it ever coming out again........Done!
I will post pics, once I Upload them to a hosting site, currently they are on my hard drive, and do not see how I can do that here?