Ford Transit 2017 - 2020 Engine Failures

[Papierowski]

Hi all,
we have a fleet of mostly of Ford Transit 2LT Diesel Engine. We are starting to see a bit of a trend with engine failures.
A customer may not check the engine oil for long periods of time and when they do the they top up with oil normally 3- 4Lts at a time.
Shortly after say 2 days the engine fails and a new engine is required, mostly cam belt is intact and oil pump belt intact as well. But yesterday we had one go and found very fine bits of cam belt and oil pump belt in the oil pump. in fact the oil pump was seized solid until it was all cleaned out. We replaced all the belts and a new oil pump, and was hoping the engine was going, it starts but runs like a pig.
My question to the group is has anyone else had the same issue with running a transit engine low on engine oil and then topping them and you get the failure shortly after?