Strange display of notes in Win Explorer

[Piotr]

Normal display:

but sometimes, for some files, one can see this:

and I haven’t figured out what may cause this.

[martinsiegrist]

Does your file contain a block?

[Piotr]

Nope, none of them.

[wim (Wim Dekeyser)]

Hi Piotr -

@Piotr

but sometimes, for some files, one can see this:

If it’s consistent for those files, please post or upload one of those.

Off-topic:

[I used to work for ELKO:)]
-wim

[Piotr]

It is random and happens sometimes for any file
PS What was your role for ELKO?.