A7rii With 100-400 GM OSS not tracking

[Thefallguy]

I have my camera set to Lock-on AF: Expand Flexible Spot.  I also have back button focus setup.  With the lens extended, it will not focus.  On the screen, it says “select focus point on/off”.  I am setting up for birds- in- flight shots.  Any suggestions?  Both camera and lens has latest firmware.

[FunWithCameras]

I haven't used an A7RII in several years, but I think it's like most of the others. If it is, there are two ways to have it track. One is to use Tracking Expand Flexible Spot (on most of my Sonys the tracking versions are tucked away in a submenu of the Focus Area menu). The other way is to set a custom button to Tracking, and hold it down when you want to track the current focus.

You say the lens "will not focus" - you mean you press the AF ON button and nothing happens? Please don't be offended, but is possible the switch on the lens is set to MF? (I only ask because that was the answer to another person's question...)