Alan M. said:
Yes, on tokens sight turned on. No on NPC sight turned on. No on fog of war and advanced fog of war, although I have just recently started playing with that to learn to use it because "DYNAMIC LIGHTING" causes extreme lagging, constant problems. How do I know? I simply clear the dynamic lighting and it instantly allows everyone to move without lag. And of course totally destroys the whole map and line of sight idea. It is awesome when it works, it just doesn't seem to work well. I suspect map size, but there is NO continuity, I suspect my internet connection and replace my router with a bigger and better system and there is no continuity, I play on a sunday morning and there is no continuity. Just saying, "Dynamic lighting does not have a consistent solution, it freezes up, lags and looks really cool when I test it but sucks, not in a good way, in game play."
It sounds like you are using Updated Dynamic Lighting - the default dynamic lighting system. It has been plagued with issues since its implementation and the developers haven't yet figured out how to make it work for all users.
One option is to revert to legacy dynamic lighting which operates a bit differently but actually works:
If you want to stay on Updated Dynamic Lighting then you will need to spend a significant amount of your own time testing various scenarios to determine what might provide you a better experience. You can try switching browsers, disabling all add-ons, turning off explorer mode, making sure your maps are all 25x25 or less, etc.
Best of luck
-Adam