Monzo.me payment not received

A friend sent me a small payment under £10 2 days ago via a monzo.me link I created and I’ve still not received it. They sent it via their Nationwide banking app, it was their first ever payment to my Monzo account, and the payment was made on a Saturday - if that’s relevant.

I asked another friend to send me a payment via the same Monzo.me link, which they did via their own Monzo account, and the payment arrived immediately. It was their first payment to me as well, however I had paid them via Monzo once months before.

Is it normal for payments via Monzo.me not to go through? And if so, why could that be?

Your friend needs to speak to their bank if the payment hasn’t arrived.