Android's USB tethering lets you reliably share internet from your phone, but it may fail sometimes. Here are some quick fixes to get it working again.
Swap the cable to another device to see if the cable or device is faulty. Inspect the HDMI for frays or exposed wires; braided cables resist damage better.
What makes range extenders so attractive compared with a more elaborate mesh system is that they are easy to install and inexpensive. Pair one with a budget-priced router, and you can build a tandem ...