I have a SharePoint 2010 Portal that uses claims based authentication with NTLM. The portal was published to TMG with site name something like staff.portal.com I have also installed certificates in SharePoint Server and updated bindings in IIS to use https and http. The AAM in SharePoint is also modified as below
default zone = http://staff.portal.com
Internet Zone = https://staff.portal.com
After configuring this I noticed few issues with SharePoint
If I access the portal externally (via TMG login screen) and go to site permissions and click on Check permissions or site collection administrators link I get a blank page. The reason is url of the page still uses http instead of https.
If I'm in the domain and try to open word or excel document it takes 2-4 minutes to load it. I suspect this is something to do with configuration in TMG. If I try to access the document externally via https the document opens instantly. To verify this I created another web application with Claims based with NTLM that is not published to TMG and if I access the documents it opens instantly.(within domain). So I'm pretty sure this is something to do with TMG.
Below is the current TMG configuration(partial). Could someone let me know if TMG is properly configured or if some additional steps are missing?