Thank you for the info. We will try to communicate this case properly to our local CAT dealership.
That is certain, at least, that we would like to disagree with the local CAT service team on the suitability of the design. If that were the case every second unit QH331 would be down with a similar failure, and we'd know about that.
One further item to check for malfunction, and to change just in case, could be the indicator for the filter.