Bluetooth Interfering with WiFi download Speeds on latest iOS13 patches (on iPhone 6S and 8)

Thanks for the feedback - based on your suggestion, I went ahead and tried 2 different channels (originally router was set to auto) and it hasn't made any difference. If I have Bluetooth enabled, I get very little download speed. Once I disable Bluetooth I can max speed. It seems like Bluetooth on the phone is impacting the WiFi on the phone running on 2.4Ghz. I have a WiFi extender that is dual band (2.4 and 5ghz) and the phones have no issue with the 5ghz band while Bluetooth is turned on.

Thanks the the feedback. It's an TP-LInk access point off of the main router and its about 4 or 5 years old. Your suggestion reminded me that my actual router was WiFi on it and we leave it turned off since it is on far end of the house. This unit is less than a year old so I enabled WiFi on it and my iphone 6S now seems to download at normal speed over 2.4ghz when connected to it. I'm not sure why the older access point would all of a sudden start to interfere with bluetooth on the 6S, but it just started after recent patching. I checked for a new firmware update for the AP and it is up to date, so maybe it's time for a newer AP to replace the one I currently have.