no limits have been reached, because the error is erroneous in itself.
support have got back to me, the issue is the number of transactions in a certain amount of time, despite the error message.
They’ve not been specific about the limit, how many transactions over what time period? I can then pass this info back to the vendor.
Monzo have also told me that there is nothing they can - obviously they can, but are unwilling to, for whatever reason.
Very disappointing.