schedule planner access from Outlook/OWA to Lotus Notes (not migrated User)

Hello community,

we have setup a Lotus Notes Coexistence wie Exchange Online EXO (Office365).. Due to using Teams all of our users have got already a mailbox in the Office365 Exchange Online environment. My question is regarding the schedule planner from Outlook/OWA to Lotus Notes User which have not migrated and still only at the Lotus Notes site available. When the schedule planer makes a lookup of the not migrated user it seams it is checking the already existing MailBox calender's of the user instead of the current Lotus notes via the Free/Busy connector. On the CoEx machine with the powershell query the Free/Busy connector is working fine. Is it possible the route this schedule queries to the Notes backed instead to the EXO mailbox due to the user is not migrated. After the user has been migrated then everything is ok it will look to the EXO mailbox calendar.

Thanks in advanced
Philipp