Although most of the issues in android 8.1 has been fixed there are some issues that need attention to fix. One of them is the USB Tethering and the WiFi Hotspot is not working.
This issue has been reported especially by the Motorola and Nexus users.
In short, you simply change the name of the APN type to blank.
Well, let’s see how to do it.
Go to setting and select Network & Internet
Select Mobile Network
Now select advanced
Go to Access Point Name
After clicking APN you will see something like this. My network provider is Airtel and you can see your APN according to the provider. Open the default APN in your device. In my case, it is the second one.
Search for APN type and click on it.
Erase all the values and type it as blank and save it. You will be able to use the hotspot and tethering after doing this.
Hope it helps.