I had this exact issue happen to me a few days ago while away from the house. Same corner of the lens cover came loose slightly and spring popped out of place. I temporarily taped the cover closed and luckily I didn't lose the spring (it came completely out shortly after it popped partially out of place). Sadly it was on xmas so I couldn't easily use the camera after this happened.

Just got around to putting the spring back in like the OP, but yeah the glue is now weaker and I can see it will happen again soon. Good to hear that someone else had luck getting just a new cover shipped to them. I do not want to exchange the whole phone (I've had none of the hardware issues like watchdog reboots that some other people are having).