Another algorithm change?

I average around 120 units per day normally but have noticed a dramatic change overnight. I realise their is still a long portion of the day left however the rate of sale is way down on normal.

I’m fairly certain after checking a few products that i’ve lost the Buy Box on a number of items overnight despite the new winners being significantly more expensive (in terms of percentages).

I know people have been questioning why their FBA products lost the buy box recently but wondered if this switch has been reversed overnight (14-15th November)?

Thanks