Access note created by senior user under account

Question

One of my colleague is facing issue with in the client's org. Like below:

There are two users(JuniorUser, SeniorUser) with same profile(UserProfile1) with Salesforce license.

JuniorUser reports to SeniorUser as per role hierarchy.

JuniorUser created an account(TestAccount).

SeniorUser create one note in the TestAccount.

JuniorUser is not able to see the note despite being owner of the TestAccount.

To replicate this issue I created 2 users with the role hierarchy in the Salesforce Developer org.

Role hierarchy:

Created 2 users as below:

Created an account record with Junior User:

Then added note in the account with Senior User:

But in Salesforce developer org the Junior User is able to access the note:

So I am not able to replicate issue in Salesforce developer org.

Can someone please help me here why the JuniorUser is not able to access the note in the client's org?