I personally use the Integrated Krome UI, that includes the Big Bank Window (All Bags). For some reason, the Big Bank Window (All Bags) is what is causing a Flickering issue for me but ONLY for my Main toon (Drakah). I do not know why. It could be an item that is only available on my character that is not on another toon. All my other characters using the same UI, using the same Bank window, have no flickering at all. But as soon as I removed the Big Bank Window on Drakah, the flickering went away. I posted this on the EQ Discord and on the EQ Forums to let them know and will see where that goes (shrug). I do believe it is item related being that it is only happening on 1 toon. Some folks said that also setting their Big Bank Window (All Bags) to the (Default) version I have in Krome, as an option, did not help them and they still got the flickering. But I am posting this just to let you know this is what I came across in case this helps any.
You can find my actual post on the EQ forums here: