your aro is just stressed.
from the move, maybe new tank mates and new tank.
i would suggest the following
1) black out back, and sides, leave only the front.
if youw ant the sides to be clear, then take off cover later, let it adjust first.
2) sitting on ground is stress for aros, all aros sit when stressed or scared.
i would seei f anyone attacks it and remove them
3) bright light can affect arowanas, plants to hide under would or coudl work but in my opinion, they also see outside whcih can stress them out.
like a small red light can stress them out, or sun shining through from outside in can do so and spook them.
from my experience, bright lights can also help stop them from easily seeing outside.
jsut like us, if its bright inside and dark outside, we cant see out, if its dark inside bright outside we see out.
somaking it bright inside, can stop them seeing outside and almost not notice the outside as much.
4) water params.
you moved to a bigger tank, hows filter capacity?
checked water params? severums can be very active, might jsut need to get used to them.
apart from that, maybe just time will heal its confidence