Since the global app configuration is not migrated, please make sure to review/configure the next settings under App administration → Gantt Suite:
The server migrates Gantt specific custom fields to cloud (those with "[Gantt]" text in them). The cloud also has such fields available. So, once migration to cloud is complete, cloud ends up with two sets of almost identical fields. The fields of server origin will have “(migrated)" added to them. You may want to delete the original cloud Gantt fields, and remove the "(migrated)" part from the migrated custom field names. Thus, you will have only the migrated server custom fields.
The migrated “Duration [Gantt]“ field becomes useless on cloud. So, please feel free to delete the field. There might be also “Duration [Gantt] (migrated)“ field, that can also be removed, after a successful migration to cloud.
Please make sure that the fields that were added to a chart configuration in server, such as start and/or end, and time tracking field, are added to the screens of migrated projects in order to prevent the errors. More information regarding chart configuration and screen updating in cloud here.
Once migrated to Cloud, please review the security schemes for the projects for the configured Impersonated view to work correctly.