Unconfirmed incoming transaction for a long time
The fees are quite low indeed. If you check the transaction instead of the address, you can notice that they are paying 51 Satoshi/Byte.

According to bitcoinfees.21.co, the recommended rate to get a transaction confirmed as soon as possible is around 220 Satoshi/byte nowadays.

So, what you can do is either wait until the transaction get confirmed, or spend the UTXO by creating a new transaction with a high fee, following a Child-pays-for-Parent (CPFP) approach.