Thanks, but that has been put forward before as a solution. However, it doesn’t address the core problem, i.e. it’s a workaround for a bug. Never mind the sheer amount of work it’s going to involve to replace all the OnMouseButtonDown events when I shouldn’t have to.
OnMouseButtonDown and OnPreviewMouseButtonDown are not the same thing and one should not simply be assumed to be an appropriate, like-for-like replacement for the other. Frankly, I don’t want my mouse clicks to tunnel; I want them to bubble and I shouldn’t be forced into using the former because of a bug.
What we’re asking here is for Epic to fix the bug.
Further to my previous rant, I’ve done some further research. You should have included the following link in your answer, as it turns out that being forced to change it to the tunnelling version is ‘by design’.