UUID is regenerated every time a pattern is saved

I'm seeing what feels like an oddity around UUIDs for pathauto pattern configurations, resulting in complexity around our config/code versioning workflow.

Repeatability

Every time a pattern is saved.

Steps to reproduce:

1. Create a pathauto pattern
2. Export configuration (drush config-export or via GUI)
3. "Edit" the pattern and save, with or without changes
4. Export configuration again

Expected result

UUID visible in the export steps remains consistent.

Actual result

The UUID is different, and is regenerated each time the pattern is saved.

Notes

This may be expected behaviour but it's causing us some workflow and config sync issues. (Although once we've stabilised our patterns it won't be an ongoing problem.)

We've been working around it in the meantime by generating UUIDs in production and manually replacing them in our local code before committing, but I'm worried this may have unintended consequences.