A7rii monitor will not activate automatically

[Mary Kay]

I recently bought an A7Rii used, but in excellent condition.  I have an A7Riv and bought the Rii to use as a backup.  I have set the Monitor/Finder to Auto, but when I lower the camera from my eye, the monitor does not go on.  I have no problem at all with the Riv.  I changed a few settings trying to fix the problem but nothing seems to work.  Other than that, the camera works perfectly.  Any thoughts?

[Olaf W.]

Check for dust and dirt on the sensor of the viewfinder. A badly aligned eyepiece can cause this begaviour, too.

[Mary Kay]

I wasn't even sure where the sensor was.  I took off the eyepiece and found it.  Cleaned the sensor and, like magic, problem solved!   Thank you so much Olaf!