Airport - upload speed a crawl
Hello! Yesterday my internet provider, Charter, reinitialized my modem, and now my upload speed has declined by a whopping 97%. It is coming in at under 0.2 Mbs, when before it was almost 6 Mbs. It is insanely slow with my wired-to-the-modem iMac, my wireless MacBook, and my iPhone. My download speed is still the same as before, and is excellent. From what I've been reading, this is a problem with the router, or how the router and modem are communicating...? Obviously, I am unclear about this, and I would welcome any help in how to fix this.
(Please explain this in fairly non-technical language, if possible. The articles I have read are too technical which is why I needed to come here.) Thank you!
macOS Sierra (10.12), null