Sending Bitcoin to a wallet but user has not received Good Afternoon,

I sent bitcoins to a user's wallet 2 days ago. Below is the transaction id:
9031b7d71ac55d2982b4451d3a0ec9ec1f80575a07afb5fe0d1a29eed5aa7841

And the wallet address:
1DDfbQNfm7UGWM4jp4CxJF631axDCafSD4

However, I was told that the bitcoin had not showed up in his wallet although the transaction has been confirmed.

May I know what may be the issue?
At time of writing, that transaction has 287 confirmations. That means it has been definitely incontrovertably irrevocably received. There can be no doubt about this. For large amounts, 6 confirmations are regarded as conclusive, for small amounts many people accept 1 confirmation. 287 is far far far beyond doubt.

The blockchain is the only truth. All data about location of Bitcoin money is in the blockchain and nowhere else†.

There is no moment in time when Bitcoin is in transit, it is always either considered by any node in the Bitcoin network to be in your wallet or in the recipient's wallet and nowhere else.

The recipient has received the money. If they say they have not, either ... 


you sent the money to the wrong address, or
their wallet is not telling them the truth 
(perhaps it isn't synchronised with the blockchain) or 
they are mistaken or 
they are lying to you.




† Use of Lightning network and other off-chain systems should almost certainly not be regarded as actual Bitcoin movements until recorded on the blockchain.