Assign second loopback address in cloud-config

Hello!
I’m trying to add a second loopback address in the cloud-config.yml file.

Neither

lo:
addresses:
- 127.0.0.1/8
- 10.1.1.2/32

nor

lo:
address: 10.1.1.2/32

did the job.

Does anyone have a suggestion how to do this?

Best regards
Sönke