3G/4G/LTE Base HAT with EC25 module stops soft reboot on Pi 3B+

I have a Pi 3B+ booting from USB SSD and this works 100% of the time (5 second boot delay enabled).

Either hard reboot (remove power) or soft reboot (shutdown -r now) both work as expected.

If I connect the 3G/4G/LTE Base HAT with EC25 module to the Pi and don’t plug in the USB cable, the Pi continues to function as expected.

If I connect the USB cable from the HAT to the Pi the hard reboot works as expected.

However, the soft reboot always hangs…100% of the time with no disk activity LED activity.

Has anybody come across this problem before or could shed some light on what the problem might be?

Did you ever find any resolution on this issue - seeing unpredictable behavior following soft reboots on my devices and wondering if there is some bigger issue at bay.