Speed   Gas Price (gwei)
SafeLow (<30m)   84
Standard (<5m)   84
Fast (<2m)   100

SafeLow Gas Price x40 in 2 days!

I'm found strange contract https://etherscan.io/address/0x82d3a142ddd44d2bd29a683f0691fbead3bccc44
Token Contract:   Gram (GRAM)

Latest 1 day 11 hrs https://etherscan.io/address/0xc801ad718521f65fab4ce45b5ae99f8436c5bd2d to this contract 77171 txns.

Maybe is it reason?