you can try to find out what's going on by redirecting fluidsynth output on stderr and stdout to a file. For example, to log both errors and normal output to a single file /tmp/fluidsynth.log, you can use:
/home/george/fluidsynth -s -i -m alsa_seq -o midi.autoconnect=1 -a alsa -g 4 /home/george/GeneralUser_GS_v1.471.sf2 2>&1 > /tmp/fluidsynth.log
The 2>&1 redirects stderr to stdout and > redirects stdout into a file.
Then restart your RPi and check the log file.
I have the suspicion that fluidsynth might works as expected, but that your MIDI keyboard is not yet fully registered as a MIDI device when fluidsynth starts. You can check that by issuing the following command: aconnect -l
Issue this twice: once when you started fluidsynth via SSH and once when you had it start on boot. Then compare the outputs.