Readarr calendar integration breaks with [homarr_domain]

[Jamy-L]

Environment

Docker

Version

0.15.10

Describe the problem

When integrating Readarr and using the external url https://readarr.[homarr_domain], the calendar event breaks with this error:
TypeError: Failed to construct 'URL': Invalid URL

When using instead a regular external url (ie https://readarr.mydomain.com) the calendar work fine.
This issue is specific to Readarr, as Radarr, Lidarr and Sonarr's calendar will work when using [homarr_domain].

Logs

TypeError: Failed to construct 'URL': Invalid URL

Context

No response

Please tick the boxes

• I confirm that I attached the proper logs
• I've read the docs
• I've checked for duplicate issues
• I've tried to debug myself