What happened to the Piled Higher and Deeper comics?

According to the latest comic, the series is on hiatus until November 2019. The unsubtle message behind the comic is that the author doesn't owe an explanation to anyone.

Not sure what happened with PhD comics, but Jorge Cham seems to be actively involved in this other project: https://www.danielandjorge.com/ It looks like the last comics were around the time of his Kickstarted book celebrating 20 years of PhD comics. Maybe he got burned out by that endeavour?

He took a break, but the comics are back now.