I’m on an up to date windows machine, have experienced this with latest stable and experimental
When collapsing a group of operators, if one is an op viewerTOP monitoring another in that group, although you can see the connection still cooking, the opviewer is no longer “seeing” the node targeted with the opviewer parameter.
This can be easily reproduced by pointing any op from the default session into an opviewer, and then collapsing the group.
Cutting and pasting the opviewer fixes it, and it seems to be inconsistent with some operators, sometimes connecting as expected and others returning nothing, with no variables seeming to change between attempts. Figured I’d let you know, in case that isn’t known behavior