Yosemite and Preview : it jumps to the first page each time you compile it

[Xavier49]

Hi,
I just installed Yosemite 10.10.5 on my imac27 and I ran LYX.
 I can view the compiled pdf file using cmd+T as usual. 
Problem is: each time I modify the file, 
the command cmd+T jumps to the first page.
Instead of staying on the same page. 
It is very much annoying and make LYX very uncomfortable. 
After having that problem, I installed the last version of LYX (2.1.5).
And of mactex-2015. 
But nothing changed.
Any idea would be greatly appreciated...