Pointer offset

Just recently, I noticed that the pointer is offset from where it is supposed to be. It is really annoying when creating polygons, because when I point to someplace to place a corner, the corner is actually placed quite a ways away from
where the pointer is. And I am now noticing that when I add waypoints to the map, they too are located offset to the pointer. Vey annoying, not to mention the gps coordinates are wrong if I am pointing at something, the gps is being taken from the offset. Any way to fix that? Using a mini mac 10.12.5 operating system

FYI, if anyone has this issue, I found the answer somewhere else on the internet. I cured it by unclicking View>Show Tab Bar - now everything works perfectly. 

Thanks Rick, that's really interesting. I have to say I'd never used that option. I can't really see the point of it, but I also can't reproduce the problem you describe. It's useful information though, I'll try and remember it in case any one else reports the same issue!