Hi Val,
in many cases this will be network related, so trying a wired connections sounds like a good idea.
Otherwise you can monitor the LED lights to see what state the device ends up in or better connect a screen to the HDMI output or use a serial console to monitor the boot process.
Using a Development version of balena might also help as you can easily connect to the device using ssh root@<device-ip> -p 22222 or directly using screen and keyboard and check connectivity and syslogs. Also the dev version gives you more console output if you are using a screen or a serial console. Regarding the the RPi4 LED’s - they are actually quite meaningful , you can find a description here: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=58151#p1485558