Hello @v-mengmli-msft,
Ok! I change the ThisItem part to the name of the Excel table and it kind of works. Code now for OnChange is:
If(SharePointForm1.Mode=FormMode.New; varivari;Table1.Producto)
With this if I go to edit, it remains saved. Problem now... That selected item is set as default for every new edit and it even overwrites what would be selected for that new item you are editing. For new entries, the item is set to blank. I could leave like this... but would love if it was possible that each item has its selected item and it doesn't change even if you are editing 10 diferent entries, etc.
At least, if you go to edit an entry and you change the item from the Default overwritten one, to the one that was in the first place, it does set it to that in Sharepoint. So it's only cumbersome, but would rather if there was a fix.
Any ideas? Appreciate so much your input so far!