SUMMARY
Recently it's been taking longer than 5 minutes for InDesign Server to spin up a new instance when executed by Windows system. This issue appears to be user specific. 

SYSTEM
Operating system version: Microsoft Windows Server 2012 R2 Standard
Processors: Intel Xeon CPU E5-2690 v4 @ 2.60GHz x 4
Adobe InDesign CC Server 2017 12.0.0.81

ISSUE:
InDesign server seems to be taking a long time (> 5 minutes) during initialization.

COMMAND:
./InDesignServer.exe -configuration [name] -port [number]

OUTPUT:
Initializing InDesignServer for port 57106: ================================================================================
InDesign CC Server Version 12.0 x64 .
Copyright 1999-2016 Adobe Systems Incorporated and its licensors. 
All rights reserved. See the other legal notices in the ReadMe. ================================================================================
Fri Apr 16 12:54:43 2021 INFO [server] Initializing
Fri Apr 16 12:54:43 2021 INFO [server] Loading the application
Fri Apr 16 12:54:43 2021 INFO [server] Scanning for plug-ins
Fri Apr 16 12:54:43 2021 INFO [server] Registering 114 plug-ins
Fri Apr 16 12:54:43 2021 INFO [server] Completing Object Model
Fri Apr 16 12:54:43 2021 INFO [server] Saving Object Model
Fri Apr 16 12:54:43 2021 INFO [server] Initializing plug-ins
Fri Apr 16 12:54:43 2021 INFO [server] Calling Early Initializers
Fri Apr 16 12:54:43 2021 INFO [server] Starting up Service Registry
Fri Apr 16 12:54:44 2021 INFO [server] Executing startup services
Fri Apr 16 12:54:44 2021 INFO [server] Using configuration indesign-manager-ws-configuration-slot-22 Fri Apr 16 12:54:44 2021 INFO [server] Initializing Application
Fri Apr 16 12:54:44 2021 INFO [server] Completing Initialization
Fri Apr 16 12:54:44 2021 INFO [server] Calling Late Initializers
Fri Apr 16 12:54:45 2021 INFO [server] Image previews are off
Fri Apr 16 12:54:45 2021 INFO [server] Server Running
Fri Apr 16 12:54:45 2021 INFO [javascript] Executing File: C:\Program Files\Adobe\Adobe InDesign CC Server 2017\Scripts\startup scripts\ConnectInstancesToESTK.js
Fri Apr 16 12:54:45 2021 INFO [javascript] Executing File: C:\Program Files\Adobe\Adobe InDesign CC Server 2017\Scripts\converturltohyperlink\startup scripts\ConvertURLToHyperlinkMenuItemLoader.jsx
Fri Apr 16 12:54:45 2021 INFO [javascript] Executing File: C:\Program Files\Adobe\Adobe InDesign CC Server 2017\Scripts\converturltohyperlink\ConvertURLToHyperlinkMenuItem.jsxbin

ANALYSIS:
The application appears to be getting stuck either during or after executing C:\Program Files\Adobe\Adobe InDesign CC Server 2017\Scripts\converturltohyperlink\ConvertURLToHyperlinkMenuItem.jsxbin
This issue is user specific. In this case, the user is the Windows system. When we launch the application as a different user we do not have this problem.

ATTEMPTED SOLUTIONS:
- Restarting the application
- Restarting the server
- Deleted user specific temp files in C:\Users<username>\AppData\Roaming\Adobe\Indesign Server<version><locale>

OTHER
It's worth noting that is problem seems to be very similar to this issue:
https://community.adobe.com/t5/indesign/indesign-server-startup-memory-issues/td-p/11500657

However, we removed the user specific temp files and the application continued to take a long time to initialize.