Facing this issue too

Yes 5G will fluctuated as the phone temperature rises, like when you played heavy games. Hopefully they will fix it with an update.

Not facing heating issue even in one ui 5 and also one ui 6 for everyday normal uses but as soon as you started playing heavy games device heats up alot to the point where games gets reduce framerate and feels laggy, also notice as device temperature...

Even One Ui 5 is taking too long and One Ui 6 is much more longer.

Notice this too for a long time. Taking too much time installing application.