Hi Kenney,
We have analyzed your query. From that, we would like to let you know that the chart is working fine. Unfortunately we are unable to reproduce the reported scenario in the mentioned version 18.4.44. We have also attached the sample and screenshot used for testing for your reference.
If you still face this issue. kindly revert us with the following information which will be more helpful for further analysis and provide you the solution sooner.
1. Try to reproduce the reported scenario in the provided sample.
2. Share the details if you have done any other customizations for parent div in your sample.
Regards,
Srihari M