Tried testing the issue on chrome reported version# 72.0.3624.2 using Windows-10 with steps mentioned below:
1) Launched chrome reported version from terminal with --explicitly-allowed-ports=139
2) On chrome windows navigated to  localhost:139, seen ERR_CONNECTION_REFUSED

@Reporter: Please find the above mentioned information and provide your feedback on it which help in further triaging the issue.

Thanks!

Deleted: 916025.png 76.3 KB

	916025.png 76.3 KB View Download

Not sure what to say. We are consistently able to reproduce the issue on our Windows 10 PC. We can provide our virtual machine, if necessary.

Thank you for providing more feedback. Adding the requester to the cc list.

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I can reproduce when the Network Service is enabled (chrome://flags/#network-service)

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e6e21a4586f8dd69348f0a30fb20772ab912afd1

commit e6e21a4586f8dd69348f0a30fb20772ab912afd1
Author: Eric Roman <eroman@chromium.org>
Date: Tue Jan 08 22:35:26 2019

Make --explicitly-allowed-ports work with NetworkService.

This also makes it work in content_shell, whereas previously it was only wired up in chrome.

Bug:  916025 
Change-Id: Ic79e478d02160e2cb0727a22495c029f21447796
Reviewed-on: https://chromium-review.googlesource.com/c/1400042
Commit-Queue: Eric Roman <eroman@chromium.org>
Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Cr-Commit-Position: refs/heads/master@{#620910}
[modify] https://crrev.com/e6e21a4586f8dd69348f0a30fb20772ab912afd1/chrome/browser/ui/startup/startup_browser_creator.cc
[add] https://crrev.com/e6e21a4586f8dd69348f0a30fb20772ab912afd1/content/browser/net/net_command_line_flags_browsertest.cc
[modify] https://crrev.com/e6e21a4586f8dd69348f0a30fb20772ab912afd1/content/browser/renderer_host/render_process_host_impl.cc
[modify] https://crrev.com/e6e21a4586f8dd69348f0a30fb20772ab912afd1/content/browser/utility_process_host.cc
[modify] https://crrev.com/e6e21a4586f8dd69348f0a30fb20772ab912afd1/content/public/common/content_switches.cc
[modify] https://crrev.com/e6e21a4586f8dd69348f0a30fb20772ab912afd1/content/public/common/content_switches.h
[modify] https://crrev.com/e6e21a4586f8dd69348f0a30fb20772ab912afd1/content/renderer/render_thread_impl.cc
[modify] https://crrev.com/e6e21a4586f8dd69348f0a30fb20772ab912afd1/content/test/BUILD.gn
[modify] https://crrev.com/e6e21a4586f8dd69348f0a30fb20772ab912afd1/services/network/network_service.cc
[modify] https://crrev.com/e6e21a4586f8dd69348f0a30fb20772ab912afd1/services/network/public/cpp/network_switches.cc
[modify] https://crrev.com/e6e21a4586f8dd69348f0a30fb20772ab912afd1/services/network/public/cpp/network_switches.h