My s10 plus is locked at an fps of 30 when connect to a TV for screen mirroring not dex, i have checked all my settings which is all default. I don't understand why this is happening but before when i used usb c to hdmi adapter without usb c charging port my device gave me full 60 fps and now i have usb c to hdmi + usb c charging + usb A 3.0 (3 in 1 ) , and i have checked it to with my laptop it is my secondary display at full 60hz without and frame rate limitation.v
Can someone please help me out with this problem, i have a link to my video on youtube in which you can clearly see my device is limited to 30 fps only.
I have same issue like you. and I haven't get the answer until now. but most of my friends said that the trouble is in the cable, which is my type C is not good enough. So they suggest me to buy another new cable