110+ is fine. However I would not implicitly trust that meter. Get a regular hand held digital meter.
Need to check voltage to neutral on each of the main breakers. If voltage drops on one side and rises on the other you have a poor neutral connection. If voltage just sags or hangs steady you may have a loose hot connection. Look for evidence of heat in the breaker box. Need to remove the cover to see the wires connected to the breakers and bus. OK to just check and snug them all up tight. Also check for heat or connection issues in your transfer switch.
