Separate pull requests not functioning as expected

TL;DR

When I have "separate-pull-requests": true in my release please config, it doesn't seem to track commits and manage release PRs correctly. I'm not sure if my configuration is wrong, or I misunderstood the manifest-driven documentation somehow.

Any help would be appreciated, I'm very confused about the correct configuration here...

My config:

{
  "packages": {
    "packages/aspire-icons": {},
    "packages/aspire-ui": {},
    "apps/email-templates": {},
    "apps/keycloak-theme": {},
    "apps/webapp-customer": {},
    "apps/webapp-marketing": {}
  },
  "separate-pull-requests": true
}

My manifest:

{
  "apps/email-templates": "1.1.1",
  "packages/aspire-ui": "1.0.0",
  "packages/aspire-icons": "1.0.0",
  "apps/webapp-customer": "1.1.0",
  "apps/keycloak-theme": "1.2.1",
  "apps/webapp-marketing": "1.0.0"
}

Expected behavior

Parse commits and bump versions for only the packages whose names are within the commit message parentheses i.e. fix(email-templates): bla bla should only bump apps/email-templates

Observed behavior

The release please action is bumping versions for unrelated packages. For example, I just committed fix(email-templates): trigger release and it updated every other release PR too. For example, an unrelated package icons now has a release PR with:
```
1.0.1 (2024-03-27)
Bug Fixes
```
email-templates: trigger release
email-templates: trigger release
webapp-customer: test patch semver

And the same with every other package in the monorepo.

However, sometimes when we merge large PRs with a bunch of commits, it updates the correct release PRs related to those commits.

Action YAML

on:
  push:
    branches:
      - main

permissions:
  contents: write
  pull-requests: write

name: Release Please

jobs:
  release-please:
    runs-on: ubuntu-latest
    steps:
      - uses: GoogleCloudPlatform/release-please-action@v4
        id: release
        with:
          token: ${{ secrets.RELEASE_TOKEN }}

Log output

No response

Additional information

The name in the package.json of each package is the same as what I'm including in my commit mesasge i.e. fix(package-name), except for ones like @aspire/ui for which release please seems to tag as just ui, so I commit as fix(ui).

googleapis / release-please-action