Entering Due Date Of New TODO Throws Error / Fails To Save

[compumatter]

What is your set up?

Self Hosted Server

Version

3.4.3

Describe the issue

When adding a new or editing an existing 'todo' and only IF you enter a Due Date, the record fails to save and throws a message: server error

Video shows it in action:
https://www.youtube.com/watch?v=s_puk6c7jjY

Error Logs (LEANTIMEFOLDER/storage/logs)

However I do not see anything in my nginx or php error logs.
I do see this in the browser console log:
compiled-frameworks.3.4.3.min.js:1 POST https://projects.compumatter.biz/tickets/showTicket/781 500 (Internal Server Error)