Split payment shows duplicate contact

Issue:
Around a week ago, the split payment functionality started to show some of my contacts twice after I select them to split payments with. I am attaching a screenshot that shows Kathrin twice even though I only clicked her once. In the contacts part of the Monzo app, she also appears twice. Once with her full name and once with just her name. This was working fine for years until a few days ago. It’s very annoying because I have to manually remove one of the duplicates every time I split a payment.

Details to reproduce:
Choose a payment. Click “split”. Select the contact. It will appear twice.

OS:
Android 12

Device:
Google Pixel 6 Pro

App Version:
5.20.0

Screenshots:

It also happens with Matt: