Hello, Xmptroubles.
May I ask if your monitor works properly after connecting the output device and selecting the correct signal source?
In addition to flashing blue, are there other colors such as green and red that alternate?
Please refer to the link below, reset the monitor to its initial value, and confirm if the issue still exists.
https://www.asus.com/support/FAQ/1013113/Thank you.
Due to the ongoing regional holidays, my responses may be slightly delayed.
Thank you in advance for your patience. 🙂