I had a problem a while ago with the circular reference from hell, in 4.27.
It’s still very much alive, I assume also in 5.
I think something is done to mitigate crashes and damage, but long chains of references are never a good thing. Using interfaces is a great way to break these chains at source, and is recommended.
But also becoming aware of how these chains build up, and avoiding them by just by habit.
There’s a util that will find the worst ones for you