I found this compatibility list, but I'm not sure it's up to date:
https://dlcdnets.asus.com/pub/ASUS/Accessory/ROG_STRIX_GO_2.4/Phone_support_list.pdfAnyway, the headset used to work fine with my Samsung Galaxy S10, which is expected according to the list above.
Now I have the Samsung S21 Ultra and the headset doesn't work.
There is connectivity and I can see 'headset' under the 'media' configuration in Android. I'm even able to skip songs, pause them, etc. But there is no sound! No sound comes from the headset. The microphone I haven't tested, but it's irrelevant at this point.
Is there any way to fix this? I'd be amazed if the headset just wouldn't work with state of the art smartphones.