can't load integrations while creating Apigee Proxy with Integration target

[Beidou]

Hi experts, 

I have created several integrations and tested them successfully as below. 

However, when I tried to create Proxy with option "Integration target", it will be keeping loading integrations. 

Appreciate any suggestions.

[Beidou]

It was resolved automatically today. However, I still don't know the root cause. The integrations I created were in Aisa-north and Asia-northeast.