Hi and welcome,
Ableton Live ReWire is initialised. There is an issue, because Ableton Live installs a ReWire component to an unexpected folder, and then there is a mismatch in ReWire in Cubase.
Since Cubase 9.5, the ReWire is not initialised by default once starting Cubase. You have to enable it manually.
The solution for you is to find the ReWire component and remove it.