Cannot save the waveform shape of the Chorus plugin

I noteiced that every time I select the sine wave in chorus plugin and reopen the project, the waveform selection is reset to the triangle wave. Other values are OK.

[Steps to reproduce]
1, Open a project
2, Insert a chorus plugin which included in Cubase
3, Select the sine wave with the waveform shape toggle switch
4, Save and reopen the project
-> Result = reset to the triangle wave

I’ve tested in Cubase 8.5.30 too and the result was the same as in Cubase 9.0.10.

P.S. I tested Studio Chorus plugin in Cubase 9.0.10 / 8.5.30 and Chorus plugin in Wavelab Elements 9.0.35 today and the same thing happened. In addition, preset also doesn’t work for this. I’ll use 3rd party plugins for now, thanks.