Regex tokens for start/end of string not working?

[andarotajo]

I'm really new to vector and trying to get my first file log working and stumbled upon this problem when playing around with the VRL playground. I have the following event:

{
  "file": "/var/log/home-assistant/home-assistant.log",
  "host": "d272443a2595",
  "message": "2025-06-09 19:08:03.406 WARNING (MainThread) [alexapy.helpers] message",
  "source_type": "file",
  "timestamp": "2025-06-09T17:10:26.246103748Z"
}

Parsing it with the following script didn't work:

. |= parse_regex!(.message, r'^(?P<timestamp>\d{4}(?:-\d{2}){2}\s(?:\d{2}:){2}\d{2}\.\d{3})\s(?P<level>[A-Z]*)\s\((?P<thread>\w*)\)\s\[(?P<component>.*)\]\s(?P<message>.*)$')

But when I remove the ^ and $ from the beginning and end of the regex it works. Am I just doing something wrong here?