The black beads seem to be some kind of scale. I doubt it's a cause, more likely a symptom, but I'm sure it's not helping the health of the tree.

Magnolia can suffer from transplant shock, especially if it was a balled and burlaped tree which lost a bunch of roots when moved, but after 2 years it should be working through that. If it's been planted properly just make sure it has plenty of summer watering (they don't like drying out) and some fertilizing wouldn't hurt either.

The weather could be having an impact on the tree. Weather has been sort of off for a lot of places this year. But those little blobs sure do look like scale to me too. In the mature and wax encased state right now. Can you fleck one off? It's not a great way to remove them since it can damage the bark, but it can be a decent way to confirm it's scale.

It took my magnolia over six years before it had its first flower.

Check out my post from 7 years ago and compare.

Looks like Magnolia scale https://content.ces.ncsu.edu/magnolia-scale

Thank you. It does seem it is magnolia scale. What systemic product do I treat this with?
Interestingly my crape myrtle also has a black sooty deposit all over its branches right now.

Some plants when they grow more vigorously will then produce less than average flowerbuds. Depends on how and when the flowerbuds form.