Imke Feldmann notes an oddity in types in Power Query:
But this function will not return any matches. I also tried out a (potentially) slower version using Table.SelectColumns(Types, each [Value] = x[Types]) – but still no match.
What I found particularly frustrating here was, that in some cases, these lookups or filters on type-columns worked.
That behavior seems odd to me. Imke shares a link from Microsoft which explains that the behavior occurs, but the why behind it eludes me.