Hello @Flick 
Welcome back to Glitch!
Pinging services have been permanently blocked (see An update on pinging services + Glitch)! We are most likely not to see this block lifted.
You can also subscribe to Glitch’s premium plan, that way you can host your projects 24/7 by boosting your projects.
Due to slightly recent problems, Glitch figured out that pinging services caused a lot of stress on their infrastructure. Glitch didn’t function well for everyone; it was, therefore, made the hard choice to block them. If you are not satisfied with Glitch, there are also other options (see Here’s what to do after Glitch banned pinging services! GUIDE).