Windows client OSes, such as Pro, are designed for single users. By design they do not support multiple, concurrent logged in users running at the same time. This has nothing to do with technical limitations or anything, it is strictly a licensing restriction.
There are ways to work around this but they violate the T&Cs you agreed to when using Windows so I won't discuss those. The legal workarounds are the following:
- Switch from using a client OS to a server OS. All the server products support multiple users at the same time. Server OSes are designed for multiple users and thus don't prioritize local users over others. This is the correct solution in almost all cases. This requires a reinstall of the OS, a server license and a CAL for each user that will use the machine (or a per-device CAL that allows multiple users). Note that out of the box Server is still limited to 2 simultaneous RDP sessions. To support more you have to install the RDS feature as well. You might also have to make a GP change to increase the limit. There are articles online on how to do this.
- Win 11 Enterprise multi-session supports multiple users at the same time as well. However from my understanding this is only available with Azure Virtual Desktop. That is the other option and eliminates the need for you to host the machine at all. Of course there are costs for subscriptions so it depends on your needs.