I think this link might help : https://steemit.com/steem/@tarazkp/the-sbd-steem-debt-and-payouts

As what I've read on the link, this seems to be not new. But happens mostly when STEEM price fell so low which means low marketcap.

SBD has been consistently above STEEM prices for several months but it is getting printed as if it is pegged at 1 dollar. This means the Market cap is increasing faster than it should be and even though Steem has also been rising, the ratio between the two has been closing. Now that STEEM price has fallen fast and SBD is still above it and there is a lot of high priced SBD on the market, the mechanism is kicking in to try and not go too far into debt.