Zen Print Server doesn't print but doesn't give an error

Hello, I am trying to get the Zen Print Server to work so that i can use the pdfprint mode in Zen Reports. Zen Reports will create pdfs just fine, so that part is working. And the printer works fine from other applications on this computer and I have verified the printer name a bunch of times.

This is Caché 2016.2 on Windows 10. I have tried this using Adobe 11.0 and Adobe DC. I have made and started a Zen Report Print Server with

Name = "ZenPrint"

Port = "4321"

and Ping Port = "4320"

which says it is running. When I run the report with a query string of

"?$MODE=pdfprint&$PRINTSERVER=4321&$PRINTTIMEOUT=30&$PS=HMSHCFA1500"

it acts like worked just fine and in the Activity dialog in the Management Portal, the number next to "Number of reports printed successfully" increases.

But nothing ever prints. The Log doesn't seem to report any errors either so I'm not sure what's going wrong here:

<record>
  <date>2018-01-16T17:21:02</date>
  <millis>1516141262565</millis>
  <sequence>10</sequence>
  <logger>com.intersys.printserver.PrintServer</logger>
  <level>INFO</level>
  <class>com.intersys.printserver.AbstractThread</class>
  <method>drainChannel</method>
  <thread>12</thread>
  <message>Worker3 :pdfFileName=C:\Cachesys\mgr\Temp\QfaVnjbTwQlZLg.pdf in Worker3</message>
</record>
<record>
  <date>2018-01-16T17:21:02</date>
  <millis>1516141262566</millis>
  <sequence>11</sequence>
  <logger>com.intersys.printserver.PrintServer</logger>
  <level>INFO</level>
  <class>com.intersys.printserver.AbstractThread</class>
  <method>drainChannel</method>
  <thread>12</thread>
  <message>Worker3 :printerName=HMSHCFA1500 in Worker3</message>
</record>
<record>
  <date>2018-01-16T17:21:02</date>
  <millis>1516141262567</millis>
  <sequence>12</sequence>
  <logger>com.intersys.printserver.PrintServer</logger>
  <level>INFO</level>
  <class>com.intersys.printserver.AdobeThread</class>
  <method>transform</method>
  <thread>12</thread>
  <message>adobeReader=C:/Program Files (x86)/Adobe/Reader 11.0/Reader/AcroRd32.exe pdfFileName=C:\Cachesys\mgr\Temp\QfaVnjbTwQlZLg.pdf printerName=HMSHCFA1500</message>
</record>
<record>
  <date>2018-01-16T17:21:02</date>
  <millis>1516141262601</millis>
  <sequence>13</sequence>
  <logger>com.intersys.printserver.PrintServer</logger>
  <level>INFO</level>
  <class>com.intersys.printserver.AbstractThread</class>
  <method>drainChannel</method>
  <thread>12</thread>
  <message>Worker3 :count=-1 in Worker3 checking whether to close socket</message>
</record>

That looks like it is working. Any ideas?