Switching from Query Editor capitalizes random letters

Thank you for the response! Perhaps my question wasn't 100% clear. 

I'm running into an issue while trying to build reports in Power BI with data that uses a Case Sensitive unique identifier, specifically SalesForce Data. 

After doing more digging I discovered that this is working as intended. Power BI uses a Case Insensitive language. Upon closing the query editor Power BI will convert some letters to uppercase, the last post on this subject (2017) with a reply from Power BI developers confirmed that this is working as intended. 

For anyone running into this same problem, I have found a workaround and long-term solution.  

Work Around

One simple workaround is to create a numerical unique identifier for all data before uploading into Power BI. After extracting it from Power BI you can use the created Unique ID to merge the data from Power BI back into the original spreadsheet. This should solve this particular problem for anyone trying to automate data entry in SalesForce. However, this is non-ideal as it requires us to pull the data out of Power BI and perform one more step on it. 

Long-Term Solution

Apparently, SalesForce has a Case Sensitive (15 characters) and Non-Case Sensitive (18 characters) unique identifier for all objects. Unfortunately, I built out my dashboards using the Case Sensitive Unique ID, but if you were aware of this issue beforehand you could build out your dashboard building the Non-Case Sensitive Unique ID. 

I plan on using my workaround until I have time to alter my reports using the long-term solution.