Iron Golems not spawning in water

I have built an Iron golem farm : The Iron Titan from Tango Tek, but I have been experiencing issues with Iron golems not spawning in water. 

Attached are some screenshots of the Farm itself, a golem in the water (Block version) and a before and after golem on land on the same server.

Edit: This should not be seen as a duplicate of  MC-60792 .

Since  MC-60792 is about golems not able to spawn with blocks next to their head.

Mine is about golems not able to spawn in water. Which was possible in older versions. 

 

Kind regards,

Martijn