Two of my company's U1252B have burnt mark traces in their PCB.

I don't recall doing anything weird.
I was measuring the voltage and frequency of 1000Vrms signals.
Peak-to-peak voltage is max 3000V (which is higher than the written 1000V max), shouldn't it give me a warning or something?
I used the same rated CAT III 1000V Fluke 289 and 87V, and they are both perfectly fine.
I even used the BM235, which is only rated for CATII 1000V, no problem!
What should I do with them? Use them as paperweights?
