Hi @Sean_Lount and welcome,
I ran into this very issue multiple times in the past. The DO Droplet you have chosen is definitely cable of the job, so you don’t have to worry about that. If memory serves, this was a result of the PHP memory_limit being bottle-necked. This can cause a multitude of issues especially when it comes to running cron tasks. I remember my cron table filling up with tens of thousands of failed requests just like you.
At the end of the tutorial you mentioned, I go over updating the .htaccess file in order to increase the PHP memory_limit for PHP 7 from 756MG to 2GB. However, this file often gets “reset” during updates/upgrades so you end up having to put your change back in afterwards. This could be the case here.
Refer to “The Fix” in this post (Web Setup Wizard cannot pass: "Check Component Dependency"). Once you’ve made this change, you might still need to:
- Truncate
cron_schedule - Restart Apache (as superuser:
sudo service apache restart) - Wait 5 minutes for the server to catch up
Let me know how you get on.