Been having the same problem since Friday. Also on Verizon FIOS. Oddly enough, my wife also plays - going through the same router - and hasn't had any issues (knock on wood).
I did find a forum thread going back to 2015 that suggested it is a port issue. I followed the advice and seemed to have found my solution. If you open Documents\The Lord of the Rings Online\UserPreferences.ini (or UserPreferences64.ini for the 64-bit client) and go the the [Net] section, there is a setting called UserSpecifiedPort. This is set to 0 by default, which causes the game to use any port between 9000 and 9013.
Whenever I have a lockup issue - usually when swift traveling or going through a door - I exit the game, change this setting to specify a number between 9000 and 9013, and reenter the game. While there might be an initial glitch - like the game reporting the server is down or it not being able to establish a connection - I am invariably able to get into the game again even on the same character.
When playing the game, we are always switching from one server in their farm to another. A given "server"- like Brandywine or Landroval - is actually a bank of physical machines. When you go from one area to another - such as when you swift travel or go through doors or even cross a boundary like from Breeland to the North Downs - you are actually being switched over to a different physical server, whichever one is handling that region of the game currently. This is where they are currently having a problem with maintaining our connections.
Felandrond - 130 LM, Freawald - 130 Hunter, Felbeorn- 130 Beorning, Felandaborn - 120 Minstrel, Felandadan - 130 Warden, Thrimlidor - 130 Champion, Freadwulf - 130 Captain