I just ran into this in MCUX 10.3. If you go into the code analysis settings and disable problems and then hit 'apply' or 'apply and save', it discards your changes. To get it to save, you have to also change something else about the entry, like its severity.
The reason I'm disabling a warning is that there seems to be another bug that I haven't noticed before. For some reason, static variables with file scope are reported as unused function declarations, when they are neither unused nor functions declarations.