Personal hotspot is provided by your Cellular Service Provider and not by Apple Inc.
It's not always the iOS update's fault! Many things can cause phone problems. If you tell people you think it's an iOS update, it might make it harder to fix the real issue.
Remember, the right question often leads to the solution!

The Hotspot is a Carrier Specific feature. Contact your Carrier (Cellular Service Provider), the agency that issued the SIM / eSIM to you.
To activate this feature for the SIM card you are using, it is imperative to reach out to your respective mobile carrier. Contacting your carrier allows you to seamlessly enable the hotspot on your device, ensuring optimal compatibility and performance. Moreover, it is advisable to inquire about any potential limitations associated with using the hotspot feature.
Different carriers may impose specific restrictions or offer varying levels of accessibility, such as data usage caps or speed limitations. Understanding these nuances ensures a smooth and informed experience when utilizing the hotspot functionality on your iPhone. Therefore, for a comprehensive understanding of the capabilities and constraints related to your specific carrier, direct communication with them is highly recommended.
See the Pic below the Hotspot is made available based on the Mobile Data selected and the feature that is enabled by the Carrier


Please see the pic below to make it clearer that Hotspot is enabled by a Carrier on one SIM and not by the other Carrier in the same iPhone (Dual SIM).


Use these steps first
Restart the iPhone or iPad that provides Personal Hotspot and the other device that needs to connect to Personal Hotspot. Make sure that you have the latest version of iOS. On the iPhone or iPad that provides Personal Hotspot, go to Settings > General > Reset, then tap Reset Network Settings.
If Personal Hotspot is not working on your iPhone or iPad (Wi-Fi

Also, check the following
- Network coverage and stability
- Data Balance
- On your windows (See if WiFi Auto Joins is enabled)
- Also, check if you have any stronger WiFi signal around your computer.
Ask the Carrier to change the SIM if nothing works.
