About two weeks ago on Golos was implemented a new HF introducing a lot of new Consensus State parameters. Probably most interesting feature for average users would be introducing min_curation_rewards and max_curation_revards. Inside this corridor authors were granted the option to choose which % of post reward they are willing to distribute to curators.
Of course it did produce some turmoil. The first few days most of witnesses didn't bother to change the default 25/25. However as more and more witnesses have started to set max_75 finally the corridor 25/75 came. Very soon it was found out that you can publish your post suggesting 75% for curators and then to change it to 25% just before payout.
The dev team responded to it that they did not really consider it to be a "bug". However if the majority of witnesses want to disable this possibility the devs might fix it on the next HF scheduled for February 2019.
Most of witnesses did want to fix it indeed as soon as possible, so about half of them did set 50/50, another half 75/75 with the result that the curation rewards for all the posts would jump from 50% to 75% and back again depending of the actual list of witnesses.
A lot of witnesses were voted in und out of the Top nowadays, with the result that most of the time it's the 75% curation reward fixed for now. However sometimes the 50% window do still appear. Someone have even made a Telegram messaging bot informing its subscribers when the 50% window appears so they could post during that time or even change settings for the previous posts.
If you are interested you can see the actual Golos network parameters using this tool:
https://ropox.tools/chainprops#