Howard Miller

Don't use database sessions. Just don't.

Your best idea is to set up a Redis server and use that. I think there's a fair chance your problem will go away.

How have you got sessions set up (if not, the default)? Have you checked your PHP / web server error logs?

You need to read the release notes - https://moodledev.io/general/releases/4.5

This tells you that you need a minimum of Moodle 4.1.2. Which you don't have.

If you then read https://moodledev.io/general/releases/4.1 you can see that you can upgrade to 4.1 and THEN to 4.5.

BUT... you also need to think about other software versions (including PHP) to avoid problems. So, some planning is needed.

This has all been nicely tabulated for you here - http://www.syndrega.ch/blog/#php-and-dbms-compatibility-of-major-moodle-releases

I strongly recommend that you test all this on a copy of your live site.

I don't like the look of those session problems. So... the next question is, "how is your Moodle site set up?". I'm thinking about how you have caching and sessions configured. Or if there is anything else "odd" or "unusual" in play. Even if "but it's always worked fine".

I'm probably far too "old skool" but I did give it a go. My issue is that it produces correct "looking" code that often isn't quite what I wanted. Worse, if I don't notice.

The end result for me is that there is no time saving. I'm not saying "never". As somebody else said, it just moves the skill from writing the code to asking the correct question.