NotAffine

I could've sworn I tried the same thing but yeah, it works now. But only if I select the nodes (with the node tool selected) and not the whole curve (with the transform tool selected). Right?

The one who helped me combine the shapes originally said Affinity gets said to fix that since around 2015 and they still haven't done that. Of course I can't just believe such a loose statement but if that's remotely true it's pretty sad. This makes working with symmetrical shapes (which are quite common) soo much worse than in Illustrator. If you have a bigger project with symmetrical shapes you'll loose hours on these small details.

I think you didn't get the problem. 1. The snapping itself should snap them together so you don't need to do that in the first place. 2. If you do what you said and then zoom in even further, you'll see either that the shapes still don't meet or that the shapes already overlap. You can't possibly put them together just like that, there'll be always a zoom level where it doesn't fit any more.

Exactly. I managed to do it with a different method but it was a comparable effort to do so. This could be improved greatly by "just" fixing the snapping, I think. Or, if the actual problem arises because of some problems with the shapes themselves, there should be an option to see/fix those issues! Do you agree?

This only solves the issue visually. They're still two different shapes. You can see that if you zoom in quite a bit. Or if you let Designer show you the nodes.

Ah, damn, I uploaded the wrong file. Uploaded the final result but I forgot to save the history there. Uploading it here now. I'm sure you'll spot the seam in the middle of the green two curve layers. They are snapped to each other but they still have a seam that only gets bigger the further you zoom in. @Callum shuriken (1).afdesign

So I tried making a shuriken. For that, I wanted (at first) to make a triangle and cut out a bit of that in the middle. I made a quite simple shape, wanted to duplicate that, flip it horizontally and then combine those. But there remains a seam, no matter how I snap the two together. Someone on an unofficial Affinity Discord Server (credits to gromofdoom) helped me out by saying the snapping was never really working in this software and I need to overlap the two halves, combine them and then delete the unneeded nodes. Why does Affinity make such a simple task this painful? That's a pretty difficult workflow for something that wants to be an Adobe alternative. Or am I blind and there's actually a better way to do that? I attached my project file (with extended history in it!) so you can see what I did (there's much stuff I did which didn't make any sense, lol). shuriken.afdesign