Wrong mapping of overloaded functions in Quartus 24.1 Pro

I now use the following workaround:

I defined an additional signal with the same type as the module output port.
The conversion is then done in a separate assignment outside of the entity instantiation.

architecture RTL of top_level is
  signal sig_out_b : my_bool_at(port_width-1 downto 0);
begin
  U_MODULE: entity work.module
    generic map (
		port_width => port_width
	 )
	port map (
		in_a(0) => a,
		--from_my_bool_a(out_b) => b
		out_b => sig_out_b
	);
	b <= from_my_bool_a(sig_out_b);
end architecture;

Now Quartus selects the correct function.