Resistance measurement problem with digital multimeter

The Fluke meters I am familiar with are specified as +/-(given percent of measurement + given number of least significant digits). For the given info, using the 400 ohm range, this yields +/-(0.004 * 0.22 + 2 * 0.1) = +/-0.20088 or approximately +/-0.2 ohms, if the meter is accurately calibrated.

When measuring low resistance values, especially at the sub 1 ohm level, you will need to consider the impedance of your probes and the connections to the meter and the resistor. If you make a resistance measurement with your probes shorted together, you can get an idea of the resistance of you probe connections.

To more accurately measure sub 1 ohm resistors without using a Wheatstone bridge or other indirect measurement methods, I would recommend using a bench DVM with a 4-wire (Kelvin) resistance measurement capability. This will remove the resistance of your probes from the measurement.

if I connect the COM lead to the positive side and the INPUT lead to the negative side I get a result of around -23.5 to -25 mA

Your battery is flat (incapable of supplying more current) and you are measuring across the battery which IS NOT measuring the current through the two resistors at all.

By the time you measure it in the reverse direction it has got flatter. I bet if you tried it back the first way it would read even less.

Try disconnecting the two resistors from the supply and letting the meter "join-up" the two disconnected points and that's how to measure current - current is the flow of electricity through wires and not some arbitrary re-wire that bears no relation to what you are tring to measure.

Get a new battery too.