Apache http vs https reverse proxy mismatch

Question

I have a reverse proxy setup in Debian 8.2 (Jessie) with Apache 2.4.10-10+deb8u where I have two separate virtual hosts, one for http and another for https, based on the following config:

<IfDefine IgnoreBlockComment>
<VirtualHost *:80>
CustomLog /tmp/just_size.log just_size
        DocumentRoot /var/www/
        ServerName XXXXXXXXXX
        TraceEnable off
        RewriteEngine On
        RewriteCond %{REQUEST_METHOD} ^TRACE
        RewriteRule .* - [F]
        ExpiresActive On
        ExpiresByType image/gif "access  plus 1 year"
        ExpiresByType image/jpeg "access  plus 1 year"
        ExpiresByType image/png "access  plus 1 year"
        ExpiresByType audio/mpeg "access  plus 1 year"
        ExpiresByType video/mpeg "access  plus 1 year"
        ExpiresByType text/html "modification plus 5 minutes"
        CustomLog /dev/null combined env=!no-registrar
        ProxyPreserveHost On
        CustomLog /tmp/non_https.log non_https
        ProxyPass /telemetria-ws/  http://10.1.0.116:8080/telemetria-ws/
        ProxyPassReverse /telemetria-ws/  http://10.1.0.116:8080/telemetria-ws/

        ProxyTimeout 1200
    ProxyPass /ecobox-ws/  http://10.1.0.116:8080/ecobox-ws/
        ProxyPassReverse /ecobox-ws/ http://10.1.0.116:8080/ecobox-ws/


        ProxyPass / http://10.1.0.116:8080/WebService/ connectiontimeout=300 timeout=300 KeepAlive=On retry=1 acquire=3000
        ProxyPassReverse / http://10.1.0.116:8080/WebService/
        ProxySet "http://10.1.0.116:8080/WebService/" connectiontimeout=300 timeout=300


        FileETag MTime Size
        Header append X-Frame-Options "DENY"
</VirtualHost>
</IfDefine>

<VirtualHost *:443>
CustomLog /tmp/just_size.log just_size
        ServerName XXXXXXX
        DocumentRoot /var/www
        DirectoryIndex index.php index.html
        TraceEnable off

        RewriteEngine On
        RewriteCond %{REQUEST_METHOD} ^TRACE
        RewriteRule .* - [F]
        #RequestHeader set Front-End-Https "On"

        CustomLog /dev/null combined env=!no-registrar

        ProxyPreserveHost On
        RequestHeader set x-forwarded-server "https://XXXXXXX/"
        RequestHeader set x-forwarded-host "https://XXXXXXX/"
        SSLEngine On
        SSLCertificateKeyFile /etc/apache2/ssl/cert.key
        SSLCertificateFile /etc/apache2/ssl/cert.crt
        SSLCertificateChainFile /etc/apache2/ssl/gd_bundle-g2-g1.crt
        ProxyPass /telemetria-ws/  http://10.1.0.116:8080/telemetria-ws/
        ProxyPassReverse /telemetria-ws/  http://10.1.0.116:8080/telemetria-ws/

        ProxyTimeout 1200


        ProxyPass /TrackViewRealTime/  http://10.1.0.235:8080/TrackViewRealTime/
        ProxyPassReverse /TrackViewRealTime/  http://10.1.0.235:8080/TrackViewRealTime/

        ProxyPass /TrackViewLogin/  http://10.1.0.235:8080/TrackViewLogin/
        ProxyPassReverse /TrackViewLogin/  http://10.1.0.235:8080/TrackViewLogin/

        ProxyPass /TrackViewData/  http://10.1.0.235:8080/TrackViewData/
        ProxyPassReverse /TrackViewData/  http://10.1.0.235:8080/TrackViewData/

    ProxyPass /ecobox-ws/  http://10.1.0.116:8080/ecobox-ws/
        ProxyPassReverse /ecobox-ws/ http://10.1.0.116:8080/ecobox-ws/

                ProxyPass /puerto-coronel-ws/  http://10.1.0.116:8080/puerto-coronel-ws/
        ProxyPassReverse /puerto-coronel-ws/  http://10.1.0.116:8080/puerto-coronel-ws/


ProxyPass / http://10.1.0.116:8080/WebService/ connectiontimeout=300 timeout=300 KeepAlive=On retry=1 acquire=3000
        ProxyPassReverse / http://10.1.0.116:8080/WebService/
        ProxySet "http://10.1.0.116:8080/WebService/" connectiontimeout=300 timeout=300

        FileETag MTime Size
        Header append X-Frame-Options "DENY"
</VirtualHost>

I have several web services (and their WSDL) exposed from the internal IP 10.1.0.116 as you may see in the Proxy* config directives, the problem is that I haven't been able to redirect incoming plain http traffic into those web services, and they are only working using https, so I guess there must be something wrong with my VirtualHost config at port 80.

Even stranger is that when the request URL is like:

http://HOST/telemetria-ws/frioChileTempService/

I do get a response*, but an empty one with the following Response headers:

*Response seems to be HTTPS as valid certificates appear in the SOAP-UI SSL Info

But when I add the port 80 to the URL (which should be the same as above):

http://HOST:80/telemetria-ws/frioChileTempService/

The server interprets it as SSL but using a plaintext connection:

Wed Feb 22 10:52:21 ART 2017:ERROR:javax.net.ssl.SSLException: Unrecognized SSL message, plaintext connection?

Where can I be having the mismatched config? The desired would be to redirect plain http to https, but don't exactly understand what could be happening.