Power BI Iframe does not load all the data

Hey everybody, 

I have worked on a project which we share with the world through an PowerBI Iframe. 

All this worked fine for almost 2 years but since last week I am facing a diffeculty, because the data isn't completely loading anymore. 

When I look at the report in Power BI Desktop it works fine, when I look at the report in Power BI Service it looks fine, and when I publish the report as App it looks fine.

However when I watch the report through the Iframe I get issues. 

Possible issues are filtering which just keeps loading but never filters, numbers that are incorrect, or the one below that the Tooltip will not load. However those issues not always appears and not not always to the same extent. 

I also looked at the website when I was trying to fix the issue, but when something doesn't work in the Iframe the website returns an error message "429 - To many request" which made me conclude that the issue is in the Iframe. 

Has somebody faced this problem before, and can they help me how I have to debug this issue? 

I would like to hear from you!

PS. via this website you can look at the report https://www.kunstgebouw.nl/cultureel-zuid-holland-in-kaart/