Hi
Could you please go to File > Account, check the version name under "Product Information"?
Does this issue occur with other Visio drawings?
On my environment, there are no quotes added for IF function automatically.
If you click "Edit Formula", what will do you find? It could be that the formula itself is considered a value by Visio.
I suggest you modify the formula to have a check, using the format in list instead. For example, if the data type is Number, using "#,#### u" or "0" instead.
You may also modify the "list" value from "Prop.ELS.Promat" to others for a test.
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