When charging with a 30W charger the S20 FE should say "super fast charging" instead of the normal "fast charging". If it doesn't then there's something wrong with your adapter/cable.
I just checked and it says "Fast Charging". Does the stock Samsung cable support 25W?
No. 30w is not 25w. It must support the appropriate specs of the 25w pd that Samsung uses. It's the same reason you can't just plug it into a 85w macbook pro charger and expect super fast charging just because 85w is a bigger number than 25w.
You can use a 30W charger on a device that supports a maximum of 25W, you can't do vice versa.
The stock cable that comes with the phone supports 15W. Use an aftermarket cable that supports 25W or above.
I'm not saying you can't charge it with a 30W. Just that 30w doesn't necessarily mean super fast charge is supported. Also "vice versa"... you sure can charge a 30w device with a 25w charger, since almost all modern devices have variable rate logic that allow a slower charge after they negotiate on a rate.
Can you please post a link or picture including the charger and cable?
