This really is a great read and you all should read it if you haven't already.
https://github.com/Lolliedieb/lolMiner-releases/wiki/All-you-need-to-know-about-Grin-difficulty,-C29,-C31-fade-out-and-C32The Grin C31 fade out has started - or will very soon (from Jan 15th 2020). Recently I get a lot of questions about this and how this affects C31 mining. Many people are concerned about "will my rewards on that now be lower" or "should I switch to C29 or C32 instead" and similar thoughts. This is why I decided to write this article about what is behind the fade out and the implication for miners.
tl;dr: As long as no one starts mining C32 seriously your are fine to continue as well and nothing will harm your rewards. Then consider a switch to C32.