Iterative Loop giving sometimes different results

Good morning,
I hope someone can help to solve what is a mistery to me.
I have a super simple flow that loops in different excel sheets from the same file.
The flow works perfectly 99% of the time.
There are a few times however where I do not get the excpeted results. Then by simply resetting all the nodes of the flow, the results return correct.

What could be a possible reason of this strange behaviour?
Sometimes I have noticed this strange behaviour also with other nodes.

Thanks in advance to anybody that can give a possible explanation.

Hi @vstefano -

Sorry for the trouble, but I think we need more information to help. What version of KNIME are you using, and on what operating system? Are the files you’re reading in from your local machine, or a remote resource?

It would be helpful for you to upload your workflow as well, so we can try to reproduce the issue, even if sporadically.