My Rog 2 is slow charging in original charger mins 3 to 4 hours 35 to 45%
Did you using original charger and original cable that comes with phone.
Change power socket in home.
Socket should not be loosed
Change the cable to new cable and recheck.
My friend also having problem with charging he have 30watt charger. In phone it showing hyper charge but charging the phone very slow
Go to recovery mode, try to clear cache partition.
Switch off the phone. Connect the charger note down the time . after one hour, report the analysis
What logo do you see when it's charging this slow? Do you have the same slow performance on both ports?