CSV not parsed into columns despite Get Data delimiter set

Filip Vrlik I have come across a similar situation where I added some rows to a csv file and found that the added rows as well as the original header row is parsing into columns correctly, while all the original data ended up in a single column. The delimiter was a comma (,). I attempted a number of fixes and eventually found that the only difference between the rows that were parsing correctly and those that weren't, was that the files that weren't parsing correctly had some numerical values surrounded by " " (e.g. ...,"50",...). This symbol (") also appeared as the only 'quote character' in the advanced settings. I found that once I removed all the " " from the data that was not parsing correctly (e.g. ...,50,...), the entire sheet functioned properly. 

While coming to this fix, I also noticed that selecting the 'quote character' as 'none' in the advanced editor had the effect or parsing all the original data correctly, but returning null values for the new rows and the header row.

Apologies for any incorrectly used jargon, I don't have a background in tech.