Hi Lulian,
Thank you for using Syncfusion Products.
We are afraid that we were not able to reproduce the issue on our side.
Code-Snippet:
chart.PrimaryValueAxis.TextRotationAngle = 90;
We used the TextRotationAngle Property, it working fine (See the below sample code). We used to execute this with the Essential Studio V8.2.0.18.
Could you please try reproduce this issue with the below sample,
F93820-1006880789.zipRegards,
Sathish