Why is Coinbase Network fee so high at the moment?

Has anybody else noticed that Coinbase Network fee has gone up significantly?

I bought BTC there yesterday and wanted to transfer it to my HW wallet but the Network fee was 0.00070939 BTC which is about $20. If I remember correctly, it's always been about $0.5 max so ~$20 seems really excessive.

Does anybody have any idea what the fee depends on or if there's a workaround I could use to avoid paying such a high fee? Thanks.