Unwanted Easing Effects in AE 2020

Since updating to AE 2020, I'm seeing unwanted easing effects in my keyframed animations.

For example, I'll animate a photograph using keyframes going from 50% to 100%, with no easing applied, but instead of a linear expansion,  I'll see the photo grow to, maybe, 120%, then shrink back down until it reaches its final size of 100%.  

Not sure if that would really be considered "easing", but I'm not sure what else to call it, (kind of like a "bounce" effect). 

How can I achieve a plain old linear tween from value x to y?  Is there a setting I need to uncheck?

Thanks in advance.