I had a problem with using a Android phones (nothing else) on Facebook - pictures took forever to load and videos never loaded (not in the few hours I waited). I had to do a little reordering of things here, and one of the things I did was factory reset my roouter and set it up again (SSID, password, etc.) and the problem disappeared. At my daughter's house, using the router supplied by the ISP, the same problem occurs, but resetting the router didn't fix it.
Facebook on an Android, using the Facebook app, seems a bit flaky on wifi.
As far as uploading, what app are you using to upload, to where and how large a file?