However by April/May 1944 they started to move new units into Normandy and they positioned powerful armored divisions close by (21st Panzer, 12 SS Hitlerjugend, Panzer Lehr).
Why did the Germans place new units in Normandy? Were they expecting the Normandy landings?
I’ve tried to look into all the available sources of information in my essay German intelligence on operation Overlord.
According to report FMS B-675 ‘Army Group B-Intelligence Estimate (1 Jun 1944)’ By Oberst i. G. Anton Staubwasser (head of intelligence for Army Group B in 1944-45) the German High Command became convinced that Normandy would be the site of Allied landings in April/May ’44:
It is important that - for the first time in April/May - Hitler informed OB West, through General O. JODEL, as follows: "The Fuehrer has definite information that Normandy is endangered." It has not become known from, what source this news originated. This message was immediately and also later repeatedly passed on to A Gp B and all armies of the west, that is, approximately 4 weeks before the beginning of the invasion. This is also the reason for the transfer of the 91 Luftwaffe Division, several armored battalions and antitank battalions to the COTENTIN peninsula and for the assembly by OKW of the Pz Lehr Division.
Here is another piece of the puzzle. The following episode is described by Albert Speer in his memoirs ‘Inside the Third Reich’, p479
On June 1, I was at the Berghof about ten o'clock in the morning when one of Hitler's military adjutants told me that the invasion had begun early that morning. "Has the Fuehrer been awakened?" I asked. He shook his head. "No, he receives the news after he has eaten breakfast."
In recent days Hitler had kept on saying that the enemy would probably begin with a feigned attack in order to draw our troops away from the ultimate invasion site. So no one wanted to awaken Hitler and be ranted at for having judged the situation wrongly.
At the situation conference in the Berghof salon a few hours later Hitler seemed more set than ever on his preconceived idea that the enemy was only trying to mislead him. "Do you recall? Among the many reports we've received there was one that exactly predicted the landing site and the day and hour. That only confirms my opinion that this is not the real invasion yet."
Hmm… What report was Hitler referring to?