input-overlay WebSocket port setting reverts to default after OBS restart

[pyzxwjj]

Describe the bug
The WebSocket port setting for the Input Overlay plugin does not persist after OBS Studio is restarted. When I change the port from the default 16899 to a custom value in the settings dialog, it reverts back to 16899 after closing and re-opening OBS.

To Reproduce
Steps to reproduce the behavior:

Go to the top menu: Tools -> Input Overlay Settings.
Ensure the "Enable WebSocket Server" checkbox is ticked.
Change the Port from 16899 to a different value (e.g., 17000).
Click OK to save.
Completely shut down OBS Studio.
Relaunch OBS Studio.
Go back to Tools -> Input Overlay Settings.
Observe that the Port has reverted to 16899.
Expected behavior
The port number should remain the custom value that was set in the previous session (e.g., 17000).

Screenshots
Not applicable, as the behavior is a settings reversion and is clearly described in the steps to reproduce.

Additional information:

Plugin version: 5.1.0 and 5.0.3
obs version: 30.2.3 (64bit), installed from apt source
OS: ubuntu 22