Huangshan School startup stuck

I made a core board for Huangshan Pi. It was booting up fine before, but after I re-soldered the magnetic sensor, the serial communication gets stuck during initialization, as shown in the figure below:

Could anyone advise what the possible issue might be?

It’s strange that there was a long gap before the log continued again.

Tried again, but it’s still the same situation, with about five or six minutes in between:

Now there’s no problem again, which feels strange.