Iframe not displaying on a particular site

I have been able to display iframes of various sites without difficulty

For some reason the iframe below shows up blank.

<iframe src="https://seektable.reference.solutions/public/report/c9a02610466c4c0f9fce74792107d8eel" width="1000" height="1000"> </iframe>

The page itself resolves fine in a browser. I have added https://seektable.reference.solutions to my my approved iframe sources under settings.

Why might this particular domain not work when others do?

(It is my domain and the underlying web app and its report links are intended for iframe use; there is no x-site prohibition.)

Is that a valid URL? It 404’s for me.

Sorry about that - I had a typo at the end

iframe works now - thank you

But I also note that there seems to be a restriction on how wide I can set an iframe to be - is there any way to change that?

   <iframe src="https://seektable.reference.solutions/public/report/c9a02610466c4c0f9fce74792107d8ee" width="1200" height="1000"> </iframe>