Older dog and puppy don’t play anymore

When we originally got our puppy (who is now 18 weeks) our big dog didn’t want anything to do with him, at about 11-12 weeks he started playing with him a couple times a day, submitting, taking turns and now he doesn’t want to play with the puppy at all. The puppy is demand barking now and it seems soon as he starts doing that at the older dog, the older dog is over it. Our older dog even used to initiate play. It just sucks because we got the puppy also because our older dog loved other dogs and seemed to want a friend and now never plays. I had so much hope when they finally started playing when he was smaller and now it’s gone 😭