Hopefully the mystery behind GP staking will be solved...

Staking perfectly fine for me here still. Rewards seem to be getting a little bigger but that could just be network fluctuation
I guess you have to have the inside info to be able to get 500%, because nobody else is. People can copy and paste all the code they want, the block explorer contains evidence showing staking at varying percentages, depending on the size of the blocks. If this is intentional, then it should be explained.
The majority of the users aren't even familiar with coin control, let alone digging through code. If this is meant to be brought to the masses, more information needs to be given, in laymen terms.
The bottom line is this coin behaves much different than other PoS coins, and there has been no rational explanation as of yet. "Just wait a month" doesn't cut it.
Whoever actually wrote this code should have knowledge to answer the questions that have been brought forth.