I have 2 external monitors, one is connected directly to the Macbook Pro. The other is through a Dock with DisplayLink.
Everything has worked well until when updating to version 227 of Safari Technology Preview it started doing this:
If I leave the window on the monitor connected by DisplayLink and wait for the computer to show the screen saver and react the equipment. The browser closes with this error:
The error report is:
https://pastebin.com/BSnUEuAk
If I repeat the process leaving the window on the monitor that is connected by USB it does not close.