renumbering error

I have just started t use dynamo and i am trying to renumber the mark value in revit and also adding few zeros in front of the number. It looks like it is working in dynamo (below in red) but it is not updating it correctly in revit as the number comes up without the added zeros: LF-0001 in dynamo vs. LF-1 in revit. Does anyone know what could be wrong? Thank you in advance.

There’s nothing that would cause characters to simply be removed. I’d guess the additional list structure is causing your values not to be written to the elements correctly. Remove the List.Create node. There’s no reason for it and it’s what’s making your Mark values have a sublist of values instead of a singular list.

i removed that node and now it is working perfectly, thank you!