It sounds to be like your client changes aren't making it to the EWA side for sure. I'd try restarting IIS, though keep in mind that it will disconnect anyone using it, so make sure to not do that during operational hours obviously. There are two cache pools you need to be aware of.
First is internet explorers cache, remember epicor downloads everything the first time, so it will cache it on IE's end first.
Secondly IIS publishes its files and runs off of that in an almost frozen state, I have always have to restart IIS when I was developing web apps to get them to reflect on the web side. Give those a shot maybe after hours and see how it goes, or Epicor support might be aware of this and maybe its a bug.
Good luck and you are welcome!