Have you ever come across the case where you open your dataflow and find 2 additional steps at the end of your query? Why are Power Platform Dataflows adding steps automatically at the end?
It will be a step that replaces errors on certain columns followed by a step that transforms these columns into text.
This will happen for every untyped column of the table that’s going to be loaded. So unlike Power BI datasets, who accept untyped columns, dataflows don’t.
As text is the format that most other simple types can also be stored in without loosing their content, this is the format in which untyped columns will be stored in. But before that, all errors will automatically be removed, because these wouldn’t be translated into text.
So be sure to apply the types to your columns as you want them to be. Otherwise you will risk an automatic error-removal in your queries, that could cause trouble at the end.
Enjoy & stay queryious 😉