I have a G27 Gen 4 with very similar problems as you are describing. This pistol was purchased about a week ago and I have included photos of the damage done by the RSA and have returned the pistol to Glock for evaluation.
I have been told many times that it's NORMAL for the spring to come out of the the assembly notch when disassembling the gun.
Further, I would never reassemble the gun without returning the spring assembly to it's proper position.
You can take a look at this and I'm sure you will find it interesting.