I keep checking for updates hoping this problem is fixed. Clearly I am not the only user annoyed about this problem.
However, for the benefit of groomedmonkey (and anyone else that suffers), I've kind of got used to having to use the trackpad to zoom the preview up to size - or if using a mouse, I've set the preferences to allow double-tap to zoom in.
The funny thing is, that once you have zoomed in, the zoom factor seems to stay the same for a random amount of time before it goes back to tiny. HTH
I'm experiencing so right now. Don't know what's the deal about it, I can't zoom it or anything. The very thing I found some sort of helping here is to resize the very pdf I'm working with. Every pdf editing tool will fit for such a purpose, I use this one https://ds11.pdffiller.com yet it's a paid one and I see no sense in paying anything in order to pass away the bug, will see