It is shorted out somewhere.
56.3 ohms suggests a 100 ohm filament balancing resistor short ... or something like that.
Assuming you actually did mean 56.3ohms and not 56k3 (56,300 ohms), .... unsolder the wire from lug 8 of the tube socket and measure those DC resistances to ground again.. I mean measure the resistance to ground from the socket's lug 8 and then from the end of the free wire.
You have something wrong and can't see the forest through the trees right now.
Double check... triple check... quadruple check... makes no difference... there is a simple wiring error or you have the wrong resistor somewhere in there.