versions:update-parent 2.16.2 not respecting range when allowDowngrade is set to true

[max-schaefer-dedalus]

my project's parent pom is set to

<parent>
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>mojo-parent</artifactId>
    <version>70</version>
</parent>

When I invoke
mvn versions:update-parent -DallowDowngrade=false -DparentVersion=[,79-!)

[INFO] --- versions:2.16.2:update-parent (default-cli) @ test-update-parent ---
[INFO] Updating parent from 70 to 78

-> works fine.

However, when I invoke
mvn versions:update-parent -DallowDowngrade=true -DparentVersion=[,79-!)

[INFO] --- versions:2.16.2:update-parent (default-cli) @ test-update-parent ---
[INFO] Updating parent from 78 to 80

i.e. it does not respect the range.

With version 2.11.0 both cases work as expected.
Maybe related to #670