This is a due to the cascading settings. You will need to go into Customizations - Account Entity and then look at the 1 to many relationships for each of the related entities - notes, etc. Change the Type of Behavior to Configuable Cascading. And then change the Relationship behaviors.
From the help system.
Configurable Cascading (Any action taken on a parent entity record can also be applied to any child entity records that are related to the parent entity record. You can define the behavior for each type of action. For example, you can set it up so that if you share a record in the parent entity, any related records for the child entity are not automatically shared. But if you delete a parent entity record, any related child entity records are automatically deleted.)
If you selected the Configurable Cascading relationship type, for each of the six actions listed below, you can select the behavior for the action.
If you set all the behaviors for the actions to match the behaviors for the actions for the other relationship types, when you save the relationship, the type of behavior is automatically set to the other type. For example, if you set all the actions to Cascade All, the relationship type is changed from Configurable Cascading to Parental.
Assign (The related records will be assigned to the same user.)
Share (The related entity records will also be shared with the same user or team.)
Unshare (The related entity records will no longer be shared with the same user or team.)
Reparent (If the owner of the primary entity record changes because the primary entity record was reparented, the owner of any related records will be set to the same owner as the primary entity record.)
Delete (The related records can be deleted, unlinked from the primary entity record, or the delete action can be canceled.)
Merge (The related records associated with the subordinate record will be reparented to the master record.)
The behaviors for these actions include:
Cascade All (Apply to all related records.)
Cascade None (Apply to no related records.)
Cascade Active (Apply to active related records only.)
Cascade User-Owned (Apply to related records if they are owned by the same owner as the owner of the parent record.)
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