I believe you need to add square brackets to show LIST of values. Please see example from TT doc below ...

SWITCH / CASE

The SWITCH / CASE construct can be used to perform a multi-way conditional test. The SWITCH directive expects an expression which is first evaluated and then compared against each CASE statement in turn. Each CASE directive should contain a single value or a list of values which should match. CASE may also be left blank or written as [% CASE DEFAULT %] to specify a default match. Only one CASE matches, there is no drop-through between CASE statements.

    [% SWITCH myvar %]
    [% CASE value1 %]
       ...
===>[% CASE [ value2 value3 ] %]   # multiple values
       ...
    [% CASE myhash.keys %]         # ditto
       ...
    [% CASE %]                     # default
       ...
    [% END %]
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See: TT Directives: Conditional Processing