What’s strange is that you still have the old Housings_xxxx libs in the list even thought you mentioned that you installed the version 5 backport libs.
And as you mentioned you are behind a proxy this might explain why you have trouble
You might want to take a look at this faq topic as it explains in detail how to install a specific library version locally: How can i install a specific version of the footprint library?
But regarding footprint assignment have a look at this FAQ article: How can i assign a footprint to a symbol?