Would a range extender increase my Internet speed? I thought it would be, but in fact, it is not. My iPhone X only gets 40Mbps from the RE200 when connected to 2.4GHz, while it gets 70Mbps from my rou

I have a 200Mbps contract with My ISP. I have an Archer A7, I tested 3 times on my iPhone X, only 59.1mbps, 63.9mbps and 79mbps, which is not fast as supposed, I contacted TP-Link Support and finally,