Craft CMS Plugin De-bug

I need someone who is competent in Craft CMS/PHP/MySQL to de-bug a problem in a Craft CMS plugin. The plugin is no longer supported by original developers and part of the plugins functionality does not work as intended. The plugin is built for Craft 3.

Plugin - https://github.com/blue-mantis/craft-private-messaging

The plugin is for private messaging between users. I am able to send messages and messages are saved to the database, but it should also create a message thread record as well which is not created upon sending a message. The plugin has all the necessary files to support and create the thread record but it is not created when sending the message and no errors are thrown.

When trying to retrieve messages in the front end using the twig variables from the plugin I get an error because there is no record of a thread for that message.

If I remove the code which tries to find the thread I can display messages on the front end, but I cannot display them in a thread view which is a crucial part of the functionality.

Attached images of database tables, as you can see the messages are created without a threadId, they are set to null and no thread records are created in the private_messaging_threads table.

Expected behaviour based on the code and documentation is is a threadId is created at the same time as a message is sent.