FK - IK switch not working?

[Philipy]

There seems to be a problem when applying a Rig to a newly created figure. I did put up a post on the Newbies section but that has had 167 views and no comments, so I suspect it means that nobody else has seen this issue?
viewtopic.php?f=6&t=24390

I have now installed and reinstalled both Blender and MPFB2 several times on two different Laptops, one running Win10 and the other Win11, using the latest nightly build each time, and I get the same thing every time on both machines.
Basically everything is fine until I press Add Standard Rig. This then shows the bone skeleton framework and if I go into Pose mode I can click on the individual bones and by pressing r, can move them individually. However, applying Helpers puts the thin circles on the model joints but they are not bound to the bones and in Pose mode they do not work to move the whole limb.
To begin with I thought I must be doing something wrong, but I'm now inclined to believe that it must actually a bug because, for me at least, it is 100% repeatable. I suspect it is the switch between FK and IK that is not working because also, the description at the top left of the window does not change to show "Armature" as it does in the Getting Started video.
I am using Blender 4.3.2 and currently MPFB2-20250114

I would be grateful for any help or advice, please?