Wifi and Bluetooth not working simultaneously

Question

I dual-booted my laptop with ubuntu 20.04 and windows 10. In Ubuntu when I'm trying to use wifi and Bluetooth simultaneously they are interfering with each other. I'm unable to use the internet through wifi when connected to a Bluetooth headset. A quick google search showed me that they both use the 2.5GHz ISM band, which is why they are interfering. But in Windows 10 everything works fine. My laptop has a Realtek RTL8723BE network adapter which doesn't support the 5GHz band.

Solutions I have already tried

1. Turned off wifi and Bluetooth coexistence with the below command.

sudo tee /etc/modprobe.d/iwlwifi-opt.conf <<< "options iwlwifi bt_coex_active=N"

Source: https://techvorm.com/fix-wifi-not-working-slows-ubuntu-bluetooth-turned

2. Tried running this command

echo "options iwlwifi 11n_disable=1 bt_coex_active=0 power_save=0 auto_agg=0 swcrypto=1" | sudo tee /etc/modprobe.d/iwlwifi-options.conf > /dev/null

Source: wi-fi and bluetooth not working simultaneously

3. I tried to remove the backport-iwlwifi-dkms package using this

sudo apt remove backport-iwlwifi-dkms

Source: https://github.com/Dunedan/mbp-2016-linux/issues/143

4. Lastly I tried this

sudo modprobe -r rtl8723be
sudo modprobe rtl8723be ant_sel=2
echo "options rtl8723be ant_sel=2" | sudo tee /etc/modprobe.d/rtl8723-ant-sel.confecho

Source: https://github.com/Dunedan/mbp-2016-linux/issues/143

Here is the output of the lspci -knn | grep Net -A2; lsusb

02:00.0 Network controller [0280]: Realtek Semiconductor Co., Ltd. RTL8723BE PCIe Wireless Network Adapter [10ec:b723]
    Subsystem: Lite-On Communications Inc RTL8723BE PCIe Wireless Network Adapter [11ad:1724]
    Kernel driver in use: rtl8723be
    Kernel modules: rtl8723be
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 0bda:b719 Realtek Semiconductor Corp. Bluetooth Radio 
Bus 001 Device 002: ID 13d3:5a01 IMC Networks USB2.0 VGA UVC WebCam
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

Answer 1

First of all, you have made a few driver parameter selections for iwlwifi, a wireless driver for Intel devices. You have none; yours is a Realtek.

While the parameter selections do no harm, they are needless and merely take up space. I suggest that you remove them.

sudo rm /etc/modprobe.d/iwlwifi-options.conf

Second, I shall be very surprised if the device doesn’t support 5 gHz channels; let’s confirm:

sudo iwlist freq

Does your router support 5 gHz?

nmcli device wifi list

If so, I suggest that you rename the 5 gHz band in the administration pages of the router, something like redhu5 or some such and connect to it instead.

Next, you tried ant_sel=2 with no success. Please try ant_sel=1:

echo "options rtl8723be ant_sel=1" | sudo tee /etc/modprobe.d/rtl8723-ant-sel.conf

Reboot and see if there is any improvement.

Finally, as has been suggested, try setting a fixed channel in your router, either 1, 6 or 11. After making any change, reboot the router. See if any of these brings improvement.

Answer 2

You already used antenna selection. But perhaps selecting a different antenna would help, see this and this.

One action that might help diagnosing the problem is trying to see what are the differences between Win 10 and Ubuntu. See this for antenna selection, and this for Bluetooth Collaboration, and compare with Ubuntu.