Is it possible that the wireless charger is at fault.
Or it could be the cird and charging brick powering it.
Can you try another phone on the wireless charger you've purchased.
And if possible try your phone on another different wireless charger @Striker999
If I can be of any further help then please don't hesitate. Take care. 😎
Daily Driver > Samsung Galaxy s²² Ultra 256Gb in Phantom Black.
The advice I offer is my own and does not represent Samsung’s position.
I'm here to help.
@Striker999: Are you using an official Samsung wireless charger? If so, please can you confirm the model number? In the meantime, please head to Settings > Battery and device care > Battery > More battery settings, and make sure that Fast Wireless Charging is toggled on. In order for it to charge properly, the device's back should make contact with the wireless charger, and the device should be centered. Also, if you have a case or cover on your S20+, please try removing it to ensure that it isn't obstructing the wireless connection.