Steps to reproduce:

Open a Unity Project
Open Undo History via Ctrl + U. Keep this open and viewable
Create a new Animator Controller via Assets > Create > Animation > Animator Controller
Create a new state with right-click > Create State > Empty
Create a transition between New State and Exit by right-clicking on New State and clicking 'Make Transition' then dragging it onto Exit state
Select the created transition
Use the shortcut Ctrl + C to copy it
Click anywhere on the Animator graph and either right-click > Paste or Ctrl + V to paste it

Actual results: Nothing appears to be pasted. However:

Undo History has added 'Paste State Machine Data' to the history
In the Inspector, the details of the pasted transition are written, even though it is nowhere viewable in the graph. The Inspector will say that it is a state between AnyState and the state the original transition went to (Exit in this case)

Expected results: One of two results is expected. Either, the transition is pasted fully and viewable in the graph, or they aren't able to be copied/pasted at all

Reproducible with versions: 7000.0.0a18, 6000.1.0b5, 2022.3.56f1, 2021.3.45f1, 2021.3.0f1

Not reproducible with versions: -

Can't test with versions: -

Tested on (OS): Windows 11

Notes: -