They aren’t grafts on a larger tree, but our of my 32 bench grafted apples I planted April 11, 2 are actually just pushing buds now. Again, these are bench grafted apples, so I’m not sure how relevant that is to your situation.
One is a rather longish interstem that had Almata on B9 with a M111 root. My other Almata on B9 was slow to come so I thought maybe it was just a tough one for some reason and was about to give up on it, but I cut off half of the longish scion and it still seemed like there was some life and now it is finally pushing 6 weeks later. The other was a super short one-bud cleft grafted Haralred on M111 and that bud looked like it dried up - perhaps I had damaged it during grafting or it has some other issue. But when I looked closely, even thought the one bud was definitely dried up, the little nubbin of scion still looked alive and before I got around to regrafting it I noticed a small pimple like thing forming next to the dried bud and it is now a reformed bud pushing out a tiny little leaf.
I’m quite amazed that these last two are making it, but it does make me feel that if the scion still looks good it may be worth it to wait. Scott’s suggestion of adding the bark grafts sounds like a great insurance poilcy as well.
One other thought is that, particularly with your first picture, you’ve got some pretty long scions and I wonder if that makes it take longer if you have only a small section of cambium matching since that little connection has to feed the full scion. I actually think my cutting off the top half of the long Almata scion I had may have helped it since it reduced how much scion it was supporting.
Finally, in your top picture it looks like there are a lot of suckers coming up and buds on the side and those might be taking away a lot of the energy as well.