Morning Trip, when you try to measure line to neutral on a feeder that lost the neutral connection the meter is not in parallel with the feeder. You actually are in series with part of the load on the circuit.
Here is one of Rogers drawings, it may help to explain the problem.
As the drawing is now if you place your meter leads between the neutral and the hot you will read 120 volts.
Leave you meter connected but 'disconnect' the neutral at the source, now what is the meter reading?
That would depend on the size of the load on each of the hots.
The meter could read anywhere from 0 volts to just short of 240 volts.
It will also if one side reads 25 volts high the other side will read 25 volts low.
Many times a lost neutral will end up releasing smoke from appliances that do not like an extra 50 or more volts.
Sorry if I can not explain it well, perhaps Jon will step in.