Ok a lot more investigations later, I have isolated the change of behaviour. 

donecanvasdialog 1 -1 0 0 0 0 0 0 0 0 0

Which was used to reset the patcher’s sub patchers at the top left is corrupting the ability for a struct to broadcast its click through a graph. Now, can anyone on the Pd dev confirm this?

How to reproduce:

https://forum.pdpatchrepo.info/topic/10854/xy-abstraction-to-get-mouse-click-and-drag-coordinates-vanilla

In pd 0.53.2 it works

In pd 0.54.0 it doesn’t receive the click from the #0-rectangle (so it draws and emits nothing)

To fix it, remove top left the donecanvasdialog elements (2 of them)

Then reinstantiate the 3 pd Subpatches on the right

(Or you can just try the one I attach)

It is not fixed completely yet but the click gets through now. I really wonder what has changed there…

Any pointer (pun intended) welcome

p