I had enough materials to make 4 beds but only 3 were crafted, this is likely due to a variety of woods used.  But when I opened the crafting table there was no recipe showing to make a bed when i clearly had 3 wool and 3 dark oak planks.  Placed the material as needed on table to make bed, closed and reopened and now bed appears as possible recipe.

This is my guess on the reasoning and a possible repo of the issue

get 4 sets of 3 planks each different types

shift click to create 'max' beds but because of how system works it will only create 3.

crafting table will be confused thinking no more beds can be created.

place bed recipe in table to 'reset' it