Code formatting broken when selecting FLUID as Template Data Language
It has been a very long journey with https://youtrack.jetbrains.com/issue/WI-42135 until the JetBrains support crew found out that actually this plugin is the culprit.
TL;DR: Selecting "FLUID" as "Template Data Language" in the project settings causes the code formatting to go totally nuts. Indentation does not work anymore, use statements in PHP end up in a single line and some other stuff.
Version 1.4.0 of the plugin