The symptom you described can occur if the Performa General Controls control panel is replaced by the generic System 7.1 General Controls control panel. The General Controls control panel is not the same for the Performa system software (System 7.1P) and the generic System 7.1.
The two control panels are not interchangeable. The System 7.1P General Controls control panel has 16 pre-defined desktop patterns which are not editable. The System 7.1 desktop patterns can be edited, however, the patterns are at a much lower resolution than the Performa desktop patterns.
If you wish to use the generic System 7.1 General Controls control panel, you will have to install the complete version of System 7.1.