Power BI not working in popup window

Hi,rbhardwaj1 .
According to your description, the power bi embedded code produced by your team was working fine before, but when the code is running in the current power bi service, the page appears to be blank and only the Power BI loader is displayed(when open a new window).
You mentioned that you haven't updated any of the code .
I noticed that the official link to the github documentation has been updated, have you checked to see if this is related to your current problem?
GitHub - microsoft/powerbi-client-react: Power BI for React which provides components and services to enabling developers to easily embed Power BI reports into their applications.
I am unable to reproduce your question due to my work environment.
If possible, please create a support ticket for more help.
The Link of Power BI Support:

Microsoft Fabric Support and Status | Microsoft Fabric 

I hope my suggestions give you good ideas, if you have any more questions, please clarify in a follow-up reply.
Best Regards,
Carson Jian,
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.