Confused on the dispaly after "add lock" on storage

I am practising https://learn.microsoft.com/zh-cn/training/modules/describe-features-tools-azure-for-governance-compliance/5-exercise-configure-resource-lock. The display don't match the images.

Steps:

1, create storage az900xliu under az900 resource group

2, Add lock lock1 on it

3, add container failed

4, navigate to az900:az900xliu:lock : NO LOCK here ( don't match the material)

5, navigate to az900:lock : lock1 is here

6, delete lock1

I repeated step 2-6 several times. And tried add lock2 under az900:az900xliu:lock, lock2 will disappear after navigate to other tab and back just like lock1. But, lock2 will NOT appear under az900:lock either.

And, I tried add lock2 under az900:lock. It appears, but after navigate to other tab and back, it disappear. Really confused on these behavior.

I tried create container after delete lock1(lock2 don't appear so I cannot delete). After click the link in error message, I navigate to az900:lock and two lock2 appear. One is under az900:lock, another is under az900:az900xliu:lock. After delete them, I successfully add container.