VOR to VOR with only the radios is probably the best way.
But then there’s the GPS workarounds: either delete the approach phase, do not put in an approach phase or let the GPS fly the approach (which will pick up the glideslope always, you just don’t see it come in).
I think it would be best to file a support ticket. We cannot know if the flaw is on the sims side or in the DC-6.
What about the various GPS mods? Are they behaving differently? Could be a sign it’s not PMDGs fault.
I tried one mod, a while back. But didn’t make a difference.
Seeing how the GPS seems to take over and not allow it back to the DC-6 (how it’s supposed to work) I also don’t exclude this is on PMDG. Also the GPS taking control when you’re in gyropilot mode on an active approach… I think that might be PMDG. Maybe they never tested that flow.
I will file a ticket at some point, but not done experimenting. Next one will be with the FBW Airbus out of the picture. Wondering if their systems might interfere.
So, debug-wise not smart, cause I did 3 things at once…
Flew the same route I’ve been flying to test… with approach in the GPS… now it worked…
But since it worked intermittently before, I’ll leave it like this for a while and see if it will stay reliable.
So another flight with an approach in the GPS. Switched to VLOC, the airplane reacted, locked on to the vertical needle and made the turn to the runway. So I was ‘yes, all my effort is paying off’… But then it started drifting off, to the left of the needle. Glideslope came, so I switched the knob to ‘Approach’, and it went… it didn’t lock…
So this is a totally new situation: it works, you’re locked in, then it stops working… 
I filed a ticket with PMDG, sharing all my observations and testing.
I don’t expect them to solve this quickly actually, but perhaps it helps them pinpoint these GPS issues.
I think something in the sim isn’t quite right, and I guess the DC6 relies on that.
PMDG responded that they are aware of the issues. And that they are talking with Asobo.
That’s about it.
Ok many thanks for updating the forum. So it is a sim issue and no amount of reinstalling either the sim or the Plane will help? Would that be a correct assumption? or a better way of putting it, another very fundamental thing that isn’t working quite right 11 months on and is again affecting add-ons!
They were not very specific, but indicated this is indeed a sim issue (referring to the standard planes with similar behaviour). There were no tips given or tricks advised. Personally I don’t believe reinstalling the sim will help. I don’t fly any other plane with that specific GPS, so I don’t know if this is also a problem in other planes.
But I have 2 workarounds… as long as they are aware of the problem.
oh well hopefully by sim update 2million we will have a flight sim with a reliable ILS capture in all circumstances.
I think with airliners we might start to see some improvement? The Fenix seems to work around all the MSFS stuff. I suspect PMDG’s 737 will try the same. But yes, this DC-6 is problematic, at least if you want to do it the official GPS-way.
Let’s see what Tuesday will bring. Maybe the pressure by PMDG has gotten through to Asobo.