Lag on one instance

I play 4 instances of EQ, i have my main the at the bottom of my screen are my 3 alts. 2 of the 3 windows at the bottom of my screen work fine. but there is one where there is a lot of lag it doesn't appear on any of the other windows including the main window. Is there any setting I can check/adjust to fix this? thank

[lax]

There's probably something different about its settings than the other windows. Check the in-game options, particularly video options, and see if it is configured differently than the others.