Having this issue that sounds like a common one. Yesterday everything was fine, today mouse cursor and top menu lags. Lags also occur when closing a file or navigating layers in the timeline. The only difference is that today I updated graphics card driver. I’ve tried suggested solutions from other topics: UI scaling settings, brush cursor settings set to none, aseprite reinstalling, installing previous version of graphics driver, using portable version of aseprite - none of them helped. No difference whether I’m using mouse or tablet, whether file resolution is 2k or 1pixel - it lags when application window is maximized. Scaling it to 1/4 size of the screen is the only solution. Eyedropper works just fine no matter what.
One more thing, brush preview on canvas is now affected by higher layers and layer’s opacity settings. That was not a thing before.
Other details:
aseprite ver. 1.2.17
4k monitor
win 10 64b
geforce card