About 1.5 years ago, I bought a 150mbps Tplink wifi adapter. Since I first bought it, I haven't been able to get more than 30mbps from my 100mbps home internet. I could get 99 with a cable. I'm looking for a solution because I have to connect via wifi. My internet speed is around 80-85, but I don't see more than 10-15 with the adapter.. With another brand, cheaper and lower-quality USB adapter, I see around 70, but since it's connected via USB, the connection frequently drops. I bought the Tplink adapter to solve this issue, but unfortunately, my speed is even lower. Also, I'm getting this speed from the wifi adapter about 50-60 cm away. I would appreciate it if you could help.

My adapter

Plugged into the PCIe 3.0 x16 slot

Motherboard: B450M MORTAR MAX