I just noticed that if your nodes (or node connection triangles) are even slightly overlapping another node, and you try to add a new node (in my video example below, a Parallel node), that the new node will be created with the input disconnected from the overlapped node.
Resolve Studio 18.0.2 / Decklink Mini Monitor / 14" 2021 Macbook Pro Max (macOS 12.5.1, M1 Max) / 32GB RAM