A long time hasn't been back to StackOverflow, but today I think there is a better option to stop the CSV query connection.

Just uncheck Save query definition checkbox in External Data Range Properties popup and then, you are fine to do whatever you want with the data, Excel will only consider the data as text value only, without any data connection, validating or refreshing or such things.

Look at the screenshots below for more reference. (Sorry I can't post images yet) [1]: https://i.sstatic.net/WUV1RuwX.png [2]: https://i.sstatic.net/EDDKfU3Z.png