puppet_agent Module can only upgrade to a version with Master when specifying other versions

Basic Info
Module Version: 4.1.1
Puppet Version: PE 2018.1.9, Agent is running 5.5.14 for test purpose
OS Name/Version: Windows 2016

(1) Apply the module on Windows Node with Specifying a higher version, for example, package_version => `6.17.0` or `5.5.20`.

Then run `puppet agent -t` on a Windows Node.

Desired Behavior: It should upgrade to the version specified or failed due to not supporting to a higher version.

Actual Behavior: Agent is upgraded to 5.5.16, which matches the PE version.

Bug: Need to know why this happens, and if we are not supporting to upgrade a higher version than PE is using, we should mention that in module document.

(2) Now agent is unexpected upgraded to 5.5.16, if I specify `5.5.14`, it won't make any changes.

Desired Behavior: I am expecting to enforce the agent version to a backward supported 5.5.14

Actual Behavior: Puppet Agent run doesn't make any changes and keeps it at 5.5.16.

From the above tests, I end up with a situation that my agent is upgraded to 5.5.16 which I never intended to from the test. This gives me a feeling that instead of arbitrary versions, I can only use this module to upgrade the agent version to the one that Master is using. Tested in Windows 2016 node but haven't check others.