Mumbai Fees changed last weekend


Why did Matic-Mumbai’s gas fees have increased this past weekend to 120GWei? As I can see, block gas used is below block gas limit; so it is not a problem of network saturation.

Block[ 22045037]= 12 GWei
Block[22045189 ]=60GWei
(in less than 290 blocks, fees have been multiplied by 10x)

Thanks and kind regards.