The Expressions view appears to have issues with unnamed/anonymous structs/unions.

Take this basic example:

struct Scope
{
    // Anonymous structure
    struct
    {
        char alpha;
        int num;
    };
};

int main()
{
    struct Scope x;
    x.num = 65;
    x.alpha = 'B';
 
    return 0;
}

x.num does not get resolved
x.$P$T0.num does get resolved

The question ths is an issue with the generated DWARF symbols from the compiler or if the symbol manager is not handling the generated symbols correctly.