If “Display Intranet Sites in Compatability View” is checked and Enterprise Mode is NOT configured for the Finesse Site, then it will run in IE8 mode.
Press F12 and see if running in IE11 or IE8 mode at the Finesse Login Page - as per below screen shot
If you see “Edge” you are running in IE11 mode. If you see “8” - its not supported (for Cisco UCCX / UCCE)!

https://technet.microsoft.com/en-us/itpro/internet-explorer/ie11-deploy-guide/turn-on-enterprise-mode-and-use-a-site-list

<rules version="1">
  <emie />
  <docMode>
                <domain docMode="edge">ucce-finesse-a.purplepi.ie:8445</domain>
                <domain docMode="edge">ucce-finesse-a.purplepi.ie</domain>
                <domain docMode="edge">ucce-finesse-b.purplepi.ie:8445</domain>
                <domain docMode="edge">ucce-finesse-b.purplepi.ie</domain>
  </docMode>
</rules>

<site-list version="2">
  <created-by>
    <tool>EMIESiteListManager</tool>
    <version>10.0.14357.1004</version>
    <date-created>04/13/2017 12:58:19</date-created>
  </created-by>
  <site url="uccx-a.purplep.ie:8445">
    <compat-mode>IE11</compat-mode>
    <open-in>IE11</open-in>
  </site>
  <site url="uccx-b.purplep.ie:8445">
    <compat-mode>IE11</compat-mode>
    <open-in>IE11</open-in>
  </site>
</site-list>

https://msdn.microsoft.com/en-us/library/ms537503(v=vs.85).aspx

A guide on IE compatibility view and x ua compatible
https://blogs.msdn.microsoft.com/asiatech/2013/10/22/how-to-add-web-site-to-compatibility-view-list-via-gpo/
http://frankcode.wordpress.com/2013/10/17/a-guide-to-ie-compatibility-view-and-x-ua-compatible/ http://msdn.microsoft.com/en-us/library/ff955275(v=vs.85).aspx

Compatibility mode for Sub domains
http://netitude.bc3tech.net/2013/09/11/add-subdomains-to-the-compatibility-view-list/

IE Proxy Script from here

@echo off
IF "%1" == "" goto toggle
IF "%1" == "1" goto turnon
goto turnoff
:toggle
REG QUERY "HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings" /v "ProxyEnable" | Find "0x0"
IF %ERRORLEVEL% == 1 goto turnoff
If %ERRORLEVEL% == 0 goto turnon
goto end
:turnon
REG ADD "HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings" /v ProxyEnable /t REG_DWORD /f /D 1
echo "PROXY ON"
goto end
:turnoff
REG ADD "HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings" /v ProxyEnable /t REG_DWORD /f /D 0
echo "PROXY OFF"
goto end
:end
@exit

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\Software\Policies\Microsoft\Internet Explorer\Control Panel]
"ConnectionsTab"=dword:00000000
"Connwiz Admin Lock"=dword:00000000