There are three issues I have, and they are all related to the proxy setup problem I am experiencing.

1. ======
   On the login page located here https://www.mydomainname.com/piwik/ I get a broken logo image. The logo image is located on the server at http://192.168.1.1:8080/plugins/Morpheus/images/logo.svg. But somehow the proxy (or piwik) responds that the logo.svg file is located here: https://www.mydomainname.com/plugins/Morpheus/images/logo.svg which is wrong, where in fact it should be https://www.mydomainname.com/piwik/plugins/Morpheus/images/logo.svg. Somehow /piwik/ gets dropped.

2. ======
   Immediately after logging in I get a redirect to a page that prompts: No input file specified. (or a redirect to https://www.mydomainname.com/ instead of https://www.mydomainname.com/piwik/) It is only after clicking back on the browser that I get redirected to the piwik website. Somehow the piwik code truncates the piwik folder during the redirect right after a successful login (back to the root folder.) This redirect brakes the page.

3. =====
   The "All Websites" page is not working (not giving me any data), only the "Dashboard" page works. "Add a new website" goes to https://www.mydomainname.com/?module=SitesManager&action=index&showaddsite=1&period=range&date=previous30&idSite=1 but it should go to https://www.mydomainname.com/piwik/?module=SitesManager&action=index&showaddsite=1&period=range&date=previous30&idSite=1

Same issue as issue 1 and 2, a redirect dropping the working folder I am in.

=== my setup ============
I am running Ubuntu, hosting VM (VirtualBox) Win10 serving:
Piwik 3.0.4 (running on IIS)
Apache 2.4 listening to :80 and :443
Apache proxy from https://www.mydomainname.com/piwik/ to http://192.168.1.1:8080
IIS 10 is hosting Piwik on http://192.168.1.1:8080

relevant parts of my httpd-ssl.conf file

<IfModule mod_proxy.c>    
	ProxyRequests Off	
	ProxyPass 		/      		http://192.168.1.1:82/
	ProxyPassReverse 	/      		http://192.168.1.1:82/
	ProxyPass			/piwik/	http://192.168.1.1:8080/
	ProxyPassReverse 	/piwik/ 	http://192.168.1.1:8080/
	RewriteRule ^(.+)$ https://www.mydomainname.com/$1 [P,L]		
</IfModule>
<Proxy "http://192.168.1.1:8080">
	SetOutputFilter proxy-html
	ProxyHTMLEnable  on
	ProxyHTMLExtended on
	ProxyHTMLURLMap  http://192.168.1.1:8080 https://www.mydomainname.com/piwik/
</Proxy>

my piwik global.ini.php file is set to:

force_ssl = 0
assume_secure_protocol = 0
;proxy_host_headers[] = HTTP_X_FORWARDED_HOST ; List of proxy headers for host IP addresses

[proxy]
host =  ; Proxy host
port =  ; Proxy port

I tried host = 192.168.1.1; port = 8080; -- but it did not fix the issue.