VPNs not working on mac

First, Hotspot Shield is a third party application - not Apple’s - so if you are having trouble with it then you should contact the support folks at that company.

Second, the current stable release of macOS is 15.6.1. Make sure your Mac is up to date.

Third and last, unless you do business or work with an entity that specifically requires it, a VPN is not typically required in the Mac world. Very often apps of this type interfere with the proper operation on the OS. A VPN also may not be as secure as one would expect or hope it to be, regardless of the marketing.

Please ref Apple Platform Security - Apple Support

+ 1

Commercial VPNs ?

They may not be what one believes they are doing for the computer and what they actually are doing behind the scenes 

They may also reduce you Internet Speeds by upwards of 30% 

https://gist.github.com/joepie91/5a9909939e6ce7d09e29

VPN: What you need to know - Apple Community

There are misconceptions that often arise when third-party products fail to function or meet user expectations.

Apple is responsible for addressing issues with its own services, applications, operating systems.

However, Apple cannot rectify user choices of third-party products  installed and used on their computers.

This responsibility lies solely with the third party to evaluate the performance of their products when used on an Apple Computer running the intended version of macOS.

In this case, as by colleague D.I.Johnson has outlined, Sequoia 15.6.1

How to contact an app developer