Anyone using a digital light meter to set up their digital camera?

My camera has under exposed a few photos just before sunset. I think maybe taking a few manual readings with a digital light meter may help me enter some better settings. Im pretty sure my 6d mark 2 camera uses TTL metering. When using some lenses close to sunset I think the TTL meter is tricked.

The Canon camera in Evaluative metering mode measures ALL the metering zones to determine exposure. It has some not-ever-revealed-by-Canon algorithms to decide how to bias readings in the brighter zones vs. biasing readings in the shadow zones, but we cannot begin to guess how Canon does it. Evaluative often gives a great exposure for many situations, it does seem to have Do What I Want. Nikon claimed it has a library of kinds of scenes programmed in, and it draws from that library on how to expose a particular pattern of metering zones. Canon does not make similar claims.
'DWIW' acronym in the Canon Evaluative metering case translates to 'Do What Ichiban Wants!', not 'Do What I Want' in the corner cases. With enough experience with the camera you can train yourself to guess what kind of Exposure Compensation will be needed in whick corner case situations.

IMHO, it is better to choose a target in the scene which YOU wish to record as a 'midtone', using the spotemeter in the camera or a handheld spotmeter. If the colors of sunset are important, meter on the colors of the sunset for more saturated colors that result when not overexposed.
Alternatively you can pick a target which belongs +2EV brighter than 'midtone', and meter that target, and use Exposure Compensation to give +2EV more exposure to that bright target
Alternatively you can pick a target which belongs -2EV darker than 'midtone', and meter that target, and use Exposure Compensation to give -2EV less exposure to that dark target

It DOES NOT have to be a 'digital meter'...digital will meter the same as an analog meter. It is the metering patterns of any camera's Evaluative which might account for observed differences. If both were Average metering, the metered result is the same.

'In shooting a sunset, the camera has no way to know what part of the scene to meter for, and what parts of the scene YOU want to be darker or midtone (like shadow areas), or lighter vs. midtone (like sunset colors) when in Evaluative mode. You can indicate what YOU want to be properly exposed in the scene, via spotmetering and setting the speed and aperture with the camera in Manual -- unless you use exposure lock to 'remember' the exposure (in an auto exposure mode the camerr will change the reading when you recompose the frame -- unless you use exposure lock)