Renovate doesn't upgrade after minor bump with ignoreUnstable when using prerelease semver versions

[Jolg42]

What Renovate type, platform and version are you using?

Renovate on GitHub, original repo: https://github.com/prisma/prisma/blob/master/.github/renovate.json

Describe the bug

The problem happens with the @prisma/engines and @prisma/engines-version npm packages which are only released in a semver pre-release style like (from npm info @prisma/engines versions)

 '2.16.0-1.359e744341f6e278d7f8564b6acfa3fd79531dc8',
  '2.16.0-2.369dae08a1d87eba8ea3ed671381dca74ba0f057',
  '2.16.0-3.4de8f31ec17e56b8766599aa86fee51dbb608c7c',
  [...]
  '2.16.0-43.a973e24a4e5194f8fe3301bfa7ff982b24f97c05',
  '2.16.0-44.854c8ba7f0dce66f115af36af24e66989a8c02a1',
  '2.17.0-1.4ec7e617c76720ebc757144e0bc16b819dd3c038',
  '2.17.0-2.47b8c42bf220a67f979b8d64273a2314a33542e2',
  '2.17.0-3.295a10a0ac32fb6dd59a2e3975ae5dfc568c9372',
  '2.17.0-4.62e1b79e1c93665abe9d3a3694eba727695dcf82'

Here is what semver parsing looks like from my runkit

I created this small repro, where I set the version to 2.16.0-43.a973e24a4e5194f8fe3301bfa7ff982b24f97c05
Expecting to see renovate upgrading it to the latest version available 2.17.0-4.62e1b79e1c93665abe9d3a3694eba727695dcf82
Instead it's only suggesting 2.16.0-44.854c8ba7f0dce66f115af36af24e66989a8c02a1 and will never upgrade the minor to 2.17 after that.
https://github.com/Jolg42/repro-renovate-engines-package/pull/1

We thought that "ignoreUnstable": true, would change something but it's the same behavior wit or without.

Relevant debug logs

from https://app.renovatebot.com/dashboard#github/Jolg42/repro-renovate-engines-package/296152739
DEBUG: packageFiles with updates
{
  "config": {
    "npm": [
      {
        "packageFile": "package.json",
        "deps": [
          {
            "depType": "dependencies",
            "depName": "@prisma/engines",
            "currentValue": "2.16.0-43.a973e24a4e5194f8fe3301bfa7ff982b24f97c05",
            "datasource": "npm",
            "prettyDepType": "dependency",
            "lockedVersion": "2.16.0-43.a973e24a4e5194f8fe3301bfa7ff982b24f97c05",
            "depIndex": 0,
            "updates": [
              {
                "fromVersion": "2.16.0-43.a973e24a4e5194f8fe3301bfa7ff982b24f97c05",
                "toVersion": "2.16.0-44.854c8ba7f0dce66f115af36af24e66989a8c02a1",
                "newValue": "2.16.0-44.854c8ba7f0dce66f115af36af24e66989a8c02a1",
                "newMajor": 2,
                "newMinor": 16,
                "updateType": "minor",
                "isSingleVersion": true,
                "releaseTimestamp": "2021-02-02T12:53:11.181Z"
              }
            ],
            "warnings": [],
            "fixedVersion": "2.16.0-43.a973e24a4e5194f8fe3301bfa7ff982b24f97c05"
          },
          {
            "depType": "dependencies",
            "depName": "@prisma/engines-version",
            "currentValue": "2.16.0-43.a973e24a4e5194f8fe3301bfa7ff982b24f97c05",
            "datasource": "npm",
            "prettyDepType": "dependency",
            "lockedVersion": "2.16.0-43.a973e24a4e5194f8fe3301bfa7ff982b24f97c05",
            "depIndex": 1,
            "updates": [
              {
                "fromVersion": "2.16.0-43.a973e24a4e5194f8fe3301bfa7ff982b24f97c05",
                "toVersion": "2.16.0-44.854c8ba7f0dce66f115af36af24e66989a8c02a1",
                "newValue": "2.16.0-44.854c8ba7f0dce66f115af36af24e66989a8c02a1",
                "newMajor": 2,
                "newMinor": 16,
                "updateType": "minor",
                "isSingleVersion": true,
                "releaseTimestamp": "2021-02-02T12:52:55.117Z"
              }
            ],
            "warnings": [],
            "fixedVersion": "2.16.0-43.a973e24a4e5194f8fe3301bfa7ff982b24f97c05"
          }
        ],
        "packageJsonName": "repro-renovate-engines-package",
        "packageFileVersion": "1.0.0",
        "packageJsonType": "library",
        "npmLock": "package-lock.json",
        "skipInstalls": true,
        "constraints": {
          "npm": "<7"
        }
      }
    ]
  }
}

Have you created a minimal reproduction repository?

https://github.com/Jolg42/repro-renovate-engines-package/
https://github.com/Jolg42/repro-renovate-engines-package/blob/master/renovate.json

• This is a really small bug, it does not need a reproduction (think small typo)
• I have provided a minimal reproduction repository
• I don't have time for that, but it happens in a public repository I have linked to
• I don't have time for that, and cannot share my private repository
• The nature of this bug means it's impossible to reproduce publicly

Additional context

[rarkins]

true is the default value. you need to set it to false

[Jolg42]

:palmface: It worked! many thanks @rarkins 💚