Fill 'missing' with intersecting curves (pen tool)

[Subclavius]

When drawing independent curves on the same layer (using the pen tool) with a fill, the fill vanishes where the curves intersect:

Is there any way this behaviour can be changed so that the fill also applies to the intersection?  I am using a fill opacity of 50% and ideally I would want the intersection also to have 50% opacity, as opposed to 2x50% opacity. I think there must be something simple I am missing but I can't find the answer anywhere (yet).  Please can anyone offer some advice

[Alfred]

Affinity Designer allows you to choose between the "Alternate (Even-Odd)" and "Winding (Non-Zero)" fill modes to address the problem, but Affinity Photo doesn’t currently offer that option.

[Subclavius]

Thank you @Alfred, that is indeed the problem.  I have put in an enhancement request for APhoto

[Dazzler]

You can actually do this in Photo.
Select the layer with the two rectangles on, and then from the top menu select Layer > Geometry > Separate Curves. That will give you the rectangles on two individual curve layers.
Now select both of those and select Layer > Geometry > Add. That will combine the two shapes into a single object that you can then fill with a single fill.
Obviously you lose the editability of the individual rectangles, but you can still move the points around if you wish.

Edit: and yes this is much easier to do in Designer!