VST transit not syncing properly

Hello

Cubase 12 pro user here.
I share a cubase project with a collaborator and we use VST Transit.
I am the owner of the project. I have created some tracks that are locked for my collaborator and he has created some that are locked for me (steinberg this is a totally crazy idea … but anyways)

All works except that when my collaborator updates a tracks or deletes some midi , i do not see these modifications on the project, even if the session is synced OK

Now if that doesn’t work i don’t see the point of using this functionnality … plus we both payed for premium accounts (we feel like we have been scammed to say the truth)

Anyone else has this problem ? How can we fix that ? Is it a steinberg server problem or something else ?

thank you