ORA-04021: timeout occurred while waiting to lock object in MView

In our environment, one program generally errors out while dropping a materialized view with "ORA-04021: timeout occurred while waiting to lock object".

This situation is happening at night when no one is monitoring the system. I am unable to find out why it is happening and if there's any way to view the programs/sessions using the materialized view that can be identified anywhere in AWR tables or Alert logs to troubleshoot the issue.

Thank you in advance for all your inputs and support in this matter.

Warm Regards,
A.S.

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