“We apologize for any inconvenience you may be experiencing while trying to view transactions made through the Monzo app using your Fluid card. We have confirmed that there are no issues on our end. We recommend reaching out to Monzo directly for further assistance”
If it’s stuck on their side it sounds like they’re deflecting. Front line support probably won’t have the technical understanding to know that, and will think that unless there’s a specific service outage that they’re aware of, that it’s not an issue on their end. They don’t seem to have a concept of app bugs being a thing that exists. Trying to report technical issues like this to front line support is borderline impossible as they seem to be trained to treat it was a support query or user error rather than a technical issue.
Long story short you’ll probably just need to wait to see if they fix it. They’ll probably be made aware of an issue with it eventually one way or another.