If it helps someone. I also had a similar problem when the new kiban-4 in the embedding displayed the kibana search bar, which I found distracting when we embed diagrams in our own analytic dashboards. Therefore, I can remove the search bar by changing the embed code as follows:
Currently, when you copy the paste code from Kibana, you get:
<iframe src="https://your-es-url.com/_plugin/kibana/?embed&#/dashboard/My-Dashboard?_g=(refreshInterval:(display:Off,pause:!f,section:0,value:0),time:(from:now-24h,mode:quick,to:now))&_a=(filters:!(),panels:!((col:1,id:'Unprocessed-Stock-Calls-(Status-%3C-3)',row:1,size_x:12,size_y:4,type:visualization),query:(query_string:(analyze_wildcard:!t,query:'*')),title:'My%20Dashboard')" height="600" width="800"></iframe>
This displays the kibana search bar by default. But you can simply change the order of embedding the code as follows, where you move the update interval to the end, it stops displaying the search bar, and the visualization loads beautifully.
<iframe src="https://your-es-url.com/_plugin/kibana/#/dashboard/My-Dashboard?embed&_a=(filters:!(),panels:!((col:1,id:'Unprocessed-Stock-Calls-(Status-%3C-3)',row:1,size_x:12,size_y:4,type:visualization),query:(query_string:(analyze_wildcard:!t,query:'*')),title:'My%20Dashboard')&_g=(refreshInterval:(display:Off,pause:!f,section:0,value:0),time:(from:now-24h,mode:quick,to:now))" height="600" width="800"></iframe>