Thanks for this! Share did the trick for the single-monitor version, it now updates both windows. It did not fix the multi-display version, still only updating the most recently created. Giving them different swapInterval values as well didn’t fix the issue, no matter which was 1 and which was 0, and no matter which order I had them flip, or having it share or not. It only ever seems to be updating the most recently created window when there’s multiple monitors. Any other ideas?