It's kind of surprising that the change is that low when an American President is basically waging a diplomatic offensive against Israel. Good news in the long run.
From the outside it looks like the American president is as strongly supportive of Israel as ever. I guess, when the competition is on who supports the Israeli right wing more, then going from 12 to 11.9999 on a 10-point scale sounds like treason, but it would be worthwhile to remember, that it is still a pretty much unqualified support of a foreign government: something no other US ally remotely enjoys.