Querying other files erasing data from the sources?

[RudeClown]

Hello, I have been working on a project where I have one file querying data from a set of other files, all found in one folder. I've gotten the query to function as expected, however I have seen a pattern of data from the source files being lost. I don't know if this is an issue in the files themselves and my import is simply reporting the accurate information, or if the queries could somehow be causing the data loss from the source files. I am very new with PowerQuery, so my question is, is it possible for a query to be causing a data loss in the source files or somehow cause the data files to evert back to a previous version? Perhaps it's replacing the data on the source file with the last information that was imported to the file I am querying from? The data that seems to be missing from the sources seems to be the data that was added to the sources between the last time the query was ran and the current query that was ran when the loss was noticed. I am at a loss to explain it and I was hoping somebody who is well experienced with PowerQuery might be able to tell me if it's even possible the query could be a cause. Thank you for any insight you may be able to offer!