Issue in exporting links in excel from record grid

I have a requirement to show the hyperlink when exported to excel from record grid . The associated DB column has a either a DOC Id or a url .

By exporting ,few fields are shown as desired (both label name with hyperlink), few are just shown with with label and no hyperlink and few are entirely skipped to show the excel.

I have the following sample code.. Is something wrong here?

a!gridColumn(
label: "File Name",
value: a!linkField(

links:a!safeLink(
label: fv!row['recordType!record.fieldname],
uri:
if(
left(
fv!row['recordType!record.docImage],
10
) = "[Document:",
document(
todocument(fv!row['recordType!record.docImage]),
"url"
),
fv!row['recordType!record.docImage]
)),
showWhen:a!isNotNullOrEmpty(
fv!row['recordType!record.docImage]),

showwhen:false
exportWhen: true,
align: "START"
),

Thanks