core: REST command not working in rest_command

The problem

I have a REST command that I want to send to a shelly device. Somehow this command is not working when part of a rest_command. But from terminal the command is working fine.

What is version of Home Assistant Core has the issue?

core-2021.3.4

What was the last working version of Home Assistant Core?

No response

What type of installation are you running?

Home Assistant OS

Integration causing the issue

rest_command

Link to integration documentation on our website

https://www.home-assistant.io/integrations/rest_command/

Example YAML snippet

# Put your YAML below this line
rest_command:
  shelly_command:
    url: "http://192.168.69.85/settings/actions?index=0&name=out_on_url&urls[]='http://192.168.69.87/light/0?turn=on'&urls[]='http://192.168.69.86/light/0?turn=on'&enabled=false"

Anything in the logs that might be useful for us?

# Put your logs below this line
Unfortunately there is no error in the logs, it seems communication to the device is fine, but parameters do not get set.
It may have something to do with the characters in the rest command. However partially encoding these characters does not help.