Adobe Analytics by itself does not convert values from uppercase to lowercase or vice versa.
There are normally 3 reasons for the case conversion:
In case of eVars, while they are case insensitive, the value we see is a result of the server that returns the data first. Because there are multiple servers sending data, it is possible for the same value to have different capitalizations.
The reason the cases are different is because it depends on the server that returns data first. Whichever server returns data first will determine the case that we see in Workspace.
Since there are multiple servers sending data, the case is determined by chance. This can happen regardless of what the date range is.
Although a company can only be on one data center at all times, however, each Data Center has thousands of reporting servers, and the data is stored on multiple servers in blocks by the month.
Therefore, the case in Workspace varies based on the date range and the server that returns its data first. There is no setting to change the case sensitivity for eVars.
For the props, they can be case sensitive or case insensitive.
Although the document https://experienceleague.adobe.com/docs/analytics/components/dimensions/prop.html?lang=en mentions that Props, by default, are not case-sensitive.
Over time Adobe's system has changed and now the default is case sensitive.
It is possible to enable case insensitivity.
However, Segments and filters is the greatest focus when changing case sensitivity.
When case insensitivity is enabled, all the data from the past would still be there. It would just show up in different line items as they have different cases.
The prop values will get rehashed, and the previous historical prop values will no longer match with the new values. This would mean that any new segments and filters would not include the prop data from before.
For example, if we are making a segment or filter by adding all cases, e.g. abc, ABC,aBC, it is not guaranteed that segments or filters would work, so the only option to report on it is to search the specific line items from the dimensions menu on the left hand rail and drop it to the freeform table.