Year and Month Current Selections

I am having the same issue with a Service, Owner and Assignment group also

Code Below:

It doesnt do the same for Owner or assignment group. It seems to only throw back all the results of Service.

Year is doing the same thing.

I assume it should be blank like Owner and Service are.

The same applies to Year & Month. Year returns everything when nothing is selected but they do work however as they should do when i do, select something,

MappingFilter = 
VAR S = ISFILTERED('Mapping'[Service])
VAR O = ISFILTERED('Mapping'[Owner])
VAR G = ISFILTERED('Mapping'[Assignment group])

RETURN 
SWITCH(
    TRUE(),
    S && O && G, CONCATENATEX ( 
        SELECTCOLUMNS(
            SUMMARIZE(               
                 'Mapping',
                'Mapping'[Service],
                'Mapping'[Owner],
		        'Mapping'[Assignment group]
            ),
            "str", 'Mapping'[Service] & "-" & 'Mapping'[Owner] & "-" & 'Mapping'[Assignment group]
        ),
       "Filter: " & [str], "; "
    ),
    S, CONCATENATEX( 
        VALUES('Mapping'[Service]),
        'Mapping'[Service], "; "
    ),
    O, CONCATENATEX(
        VALUES('Mapping'[Owner]),
        'Mapping'[Owner], "; "
    ),  
    G, CONCATENATEX(
        VALUES('Mapping'[Assignment group]),
        'Mapping'[Assignment group], "; "
    ),
    "All Selected"
)