I sent 0.1 BTC to an exchange 3 days ago but it is still not deposited and showing as unconfirmed in the web interface. It was sent during network overload period which only has gotten worse since. I tried many times to send it from Mycelium wallet but I got "Unable to broadcast" error until I increased fee to ~741sats/byte. It took a few hours or so to get 6 confirmations and it is showing as confirmed in mycelium since then. The problem is that the blockchain.info shows it as unconfirmed 3 days after. How can it be unconfirmed and have 283 confirmations? Why does this happen and what can I do? The received keeps linking to the below saying it's unconfirmed.

https://blockchain.info/tx/8856030cdb074a0fc6bc3aa65bef4b7ab02ed3978effa18978cec3b1fb87d989