Duplicate packages when using a WiFi repeater

Hi, I have a problem that only occurs on an Asus Vivobook F515KA and only when connected to WiFi via a Tplink repeater.

After running the ping utility for just a few seconds, I get 54 packets sent, 54 received and 143 duplicates.

I'm not sure if this is the only problem, as the device also disconnects quite often from both WiFis. It may be important to note that the laptop is running EndeavourOS and not Windows.

As far as I can tell, it has an RTL8821CE network card installed. And I have found some posts on the internet saying that the Linux driver for this is pretty bad.

I would be really thankful for any help you can give me.