I went to the dealer today for an oil change and he told me that there was a recall for fuel clips. (I guess they have my address to send me marketing waste and my phone to call me about marketing spam. Recall is not considered either...)
So, they replaced 8E0-201-449-G bracket/fuel clip.

...why my fuel door often won't shut if it's cold out? I have to reach inside and unlock it again, then try to shut it again, and again, until finally it locks.

Get's stuck inside... usually have to tap the side for it to come out.