I’ve noticed that occasionally Let’s Encrypt certificates will fail to provision on some of my development environments.
The most recent example I have of this is when I’ve been working on the
adding-emphemeral-redis branch of my project. They fail to provision on that branch, but not on any of my other environments.
In your case, I believe the issue is due to the length of the URLs that are being generated by Platform.sh based on the name of the branch.
Let’s Encrypt can only handle a maximum of 64 characters, and the full URL of your project
PLATFORM_ENVIRONMENT-PLATFORM_PROJECT.REGION.platformsh.site probably puts you at 67 characters.
PLATFORM_BRANCH + 7
PLATFORM_PROJECT = 13
REGION = 2-4
platformsh.site = 15
- extra characters (. & -) = 4
Keep your branch names to under 20 characters going forwards and you should no longer have this issue.