Error Oracle ORA-12704 character set mismatch when refreshing dataset

After tinkering a lot with this problem. I've figured out how to avoid the problem and it works flawlessly although I don't really understand why.

The merge step generated by the power query editor is like so:

Table.CombineColumns(#"Removed Other Columns",{"IMDSC1", "IMDSC2"},Combiner.CombineTextByDelimiter("", QuoteStyle.None),"Merged")

You get always this error:

QuoteStyle.None generated

The QuoteStyle.None function inside the Combiner.CombineTextByDelimiter makes the whole thing fail. If you remove this piece of code like so:

Table.CombineColumns(#"Removed Other Columns",{"IMDSC1", "IMDSC2"},Combiner.CombineTextByDelimiter(""),"Merged")

Magic happens:

QuoteStyle Removed

 You get your data back as you would expect.

The reason why this is the problem escapes my understanding. On top of that the documentation on these functions is less than ideal. If anyone knows why this happens let me know! I'm now curious 😋