Mint nft very Slow speed

I am in the mint nft ,Confirmation in chia blockchain is often slow. I am not sure if it is related to the size information of my picture, my picture size 2048*2048,The current rate is an average of three nft an hour

When I tried to raise the fee the effect was the same。

What fee did you use? We recommend a minimum fee of around 0.000005 XCH.