Can't use CombDLL ThOr variables in a combination cut

Using CombDLL PID variables in the combination cut of a ThOr combiner (e.g. F.SUM(F.PID_MU > 0) > 0) causes an error:

In file included from input_line_27:12:
/home/lmeyerga/stack-020921-opt/Rec/InstallArea/x86_64_v2-centos7-gcc10-opt/include/Functors/TrackLike.h:343:17: error: member reference type 'const LHCb::Particle *const' is a pointer; did you mean to use '->'?
        return d.CombDLLmu();
               ~^
                ->