Apple watch notification shows wrong transaction amount

[allthebuttons]

Issue:
I had an Uber transaction for £16.40 last night. The watch notification (exact same time so not a different transaction) shows £6.40.
Details to reproduce:
Unknown.
OS:
iOS 17.5.1
watchOS 10.6
Device:
iPhone 15 Pro
Apple Watch A2473
App Version:
Not sure how to check - latest as of 10th Aug 24
Screenshots:

[ndrw]

That is an Apple Wallet notification, not a Monzo one.

Was the original amount less than the final settled amount?