Case sensitivity has no effect on "contains (no) string" operations

What causes this issue?

For this value range expression, the operation type has been defined
either as 'contains string' or 'does not contain string'. In addition,
you have selected the 'Case sensitive' flag. However, for technical
reasons the string containment operations are always carried out as
case-insensitive by the system, regardless of the setting of this flag.

System Response

The system will not discriminate between upper or lower case strings
when the expression is evaluated.

How to fix this error?

If it is crucial for your use case to let the system behave differently
depending on the capitalization of strings, you will have to remodel the
application so that upper and lower case strings can be treated
differently. For example, this can be accomplished by using the
'equals' operations.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.