What makes my 14-month-old cry when he wakes up in the morning?
Toddlers often have changes in their sleep habits, which can include waking during the night, resistance at bedtime, and difficulty upon awakening, as your son is experiencing. It's thought that the surge of independence that occurs at this age affects many other areas of a child's behavior. Sometimes the child becomes clingier as a reaction to his growing awareness of separation. This newfound awareness could be the reason for your child's behavior. Now that he realizes you are not right there when he awakes, he's fearful until he sees you again or hears your voice. This is often a time when children become attached, or even more attached than they were previously, to a transitional object such as a teddy bear or a favorite blanket.
The best way to handle this change in behavior is to continue the same bedtime routines you have nicely established. If your son doesn't already have a favorite object, you might try offering that so when he awakens, that object might comfort him until you get there. This stage will pass in time as he continues to trust that you will be there every morning.