Hi Bernd,
Greetings from Syncfusion, we have analyzed the reported scenario and we are afraid we were not able to reproduce this issue at our end, we have prepared a simple sample of loading 10 charts in a page with 2 points in doughnut series and it is loading fine. The sample prepared to replicate the issue can be found from the below link.
Since we are not aware of your exact application scenario, we were not able to reproduce this issue at our end. It will be a great help if you could revert us by modifying the above sample to replicate your application scenario? to provide you a better solution at the earliest.
Thanks,
Michael