HP Probook Windows 10 Mobile hotspot shared from cable internet. Mac and Android can connect but can't access internet

Question

HP ProBook 430 G2 is about seven years old. Works great. I never used the Mobile Hotspot feature until last night. Moved into a place with internet provided by a standard RJ cable that plugs into the laptop.

Plugged in the cable and turned on Mobile hotspot and initially my M1 MacBook Air and my cheap Android phone both connected and got nice fast Internet access.

After some hours the devices would still connect to the PC and I could still access the Internet on the PC, but the devices connected to the PC cannot access the Internet. If I turn it off and on they might have access for some seconds or minutes.

The HP does tend to run hot. Could the networking chip(s) be damaged in such a way that it mostly works but doesn't supply Internet to connected devices? Or is it likely to be a config or driver issue?

I did a Windows update but this did not fix it. The Bluetooth also didn't work for a while but reinstalling the driver fixed that so far. But having problems with both Mobile Hotspot and Bluetooth made me suspect hardware getting flaky.

How can I at least diagnose if not fix?

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Update:

I deleted any "weird" network devices such as those from VirutalBox and a WiFi dongle I used overseas. I then did a "Network reset". This made no difference.

All three devices work on WiFi and both laptops work on hotspot shared from the Android phone's data.

Answer 1

In my case it seems that it was a combination of some weird left over network settings, and setting Sharing settings correctly.

I bought this PC used in Japan and though the system langauge is set to English there is still some low-level stuff in Japanese. Names of network items were in a mix of English and Japanese. Some must've been doubled up or just wrong.

I had some other leftover network items such as one from a virtualization solution and another for a USB internet dongle from a trip to Romania.

To clean this up I uninstalled what I could manually and then did a "Network reset" which restores all network settings back to factory settings.

This was not enough on its own. Then by Googling a found this Microsoft support page. In the past every time I'd tried anything there it was a waste of time - but not this time! Basically I had to turn on sharing properly and make sure it was from the Ethernet network item to the Local Area Network item. Previously I think I had one or both of those as English and Japanese versions. Now I only had one of each. Here are the steps from the MS page:

Option 2:

Open Mobile hotspot settings (Settings > Network & Internet > Mobile hotspot)
Turn on mobile hotspot
Under "Related Settings", click Change adapter options
Take note of which adapter is connected to the internet and which adapter is your mobile hotspot (typically named "Local Area Connection* [#]")
Right click the adapter that is connected to the internet and click Properties
Go to the Sharing tab
Uncheck "Allow other network users to connect through this computer's Internet connection". If it is already unchecked, skip this step.
Click OK
Again, open Properties > Sharing for the same adapter.
Check "Allow other network users to connect through this computer's Internet connection"
(If you get a popup that says "Internet Connection Sharing is currently enabled...", click OK.)
Under "Home networking connection:", select the mobile hotspot adapter
Click OK

When I first did this it worked for a minute or two and then my PC crashed with my first ever "green screen of death"! But since restarting it's been working great sharing internet to all my devices ever since.