Hey ​@Farfaraway, thanks for flagging this! I’m sorry to hear Figma is not functioning as expected when your monitor is connected and I’d like to help troubleshoot further.
 
To help us take a closer look, could you please confirm: 

1. The model and resolution of your external monitor
2. The OS and GPU you are using and whether these are both updated to the latest versions 
3. Is this issue occurring with Figma open in the desktop app or the browser and do you see performance drop in any other applications when your monitor is connected?
    

In general, users have reported that they tend to see a decrease in performance when their external monitor is contributing to higher CPU usage on their devices thus also impacting performance in Figma. 

Thank you for your help here confirming this information!

Hi, my monitor Xiaomi 4k RMNT27NU resolution 3840x2160, tried to open figma as in desktop application and in the browser, the problem persists. In other programs there is no problem, even in Cinema 4d everything is smooth, only in Figma, all the drivers are updated to the latest version, on the laptop installed OC WIndows 11 64 bit

Hi ​@Farfaraway, I want to sincerely apologise for the delay in getting back to you since August. 

I’ve gone ahead and submitted a support ticket on your behalf so our technical quality team can investigate this further. Your ticket number is #1493638 for reference. Someone from support should be in touch with you soon! 

Appreciate you bringing this to our attention, and I’ll make sure it gets looked into. Thanks again for your patience, and please don’t hesitate to reach out if you’d like to share any additional details in the meantime.