Never seen this error before

I’m still within all the limits so I’m curious if anyone else has gotten this in the past?

What were you trying to do? There are limits on some transactions etc.

I think this is the message you get when the card used to pay using the link (that is, the non-Monzo card) has made the maximum allowable payments in the 30 day period.

This would be why checking your own limits doesn’t show anything wrong.