Hi Rohan,
Yes, what I observed with your image not booting is with a monitor connected to my RPi 4B 4GB model! Complete blank screen. It just doesn’t boot! When I swap-out the latest Ubiquity image (2020-02-10) μSD card with my Ubuntu 18.0.4 μSD card it boots just fine as I watch the boot process on my connected monitor. BTW, we have not installed the RPi 4B on our Ubiquity Magni robot yet. The Ubiquity Magni still has the factory installed RPi 3B with whatever (release date) Ubiquity image it came with.
Thanks
-Ravi