Aloha S,
By default Cubase on Mac will run in 32 bit mode.
To change this behavior to 64 bit mode do the following:
1-Go to your Applications folder and find the Cubase app.
2-Select it and hit Command ‘I’. (get info)
3- Untick the lil box that says: ‘use in 32 bit mode’
4-Restart Cubase and ‘bob’s yer uncle’.
Good Luck!
{‘-’}