PowerShell/.NET Regular Expression for SemVer 2.0

SemVer2.ps1

# Pubic Domain. No rights reserved. No warranty.

# Reference:
# https://github.com/semver/semver/blob/master/semver.md
$VersionRegex = [regex] '(?nx)
    ^
    (?<Version>
        (?<Numbers>
            ( 0 | [1-9][0-9]* )
            (
                \.
                ( 0 | [1-9][0-9]* )
            ){2}
        )
        # Pre-release tag
        (
            -
            ( 0 | [1-9][0-9]* | [0-9]*[a-zA-Z-][0-9a-zA-Z-]* )
            (
                \.
                ( 0 | [1-9][0-9]* | [0-9]*[a-zA-Z-][0-9a-zA-Z-]* )
            )*
        )?
        # Build metadata
        (
            \+
            [0-9a-zA-Z-]+
            (
                \.
                [0-9a-zA-Z-]+
            )*
        )?
    )
    $
'

Your regex doesn't match a single valid version string out of 35.

See: https://regex101.com/r/wk7CDs/1

See also a valid regex and related discussion: semver/semver.org#59 (comment)