Sycamore tree

Would you take a picture where the trunk enters the ground and attach it to this question?
This could be drought stress combined with winter dieback. Was the tree given extra water last summer and last fall during the dry times in September and October? Thank you.

Here is requested photo

Here is requested photo

Thank you for the additional picture.

I see frost cracks in the trunk that have started to enclose, as the outer bark is loosening. These can’t be repaired, but you can prevent more cracks by shading the trunk on the south and west sides over winter, and removing the shading device in spring. See the “sunscald” section here- https://extension.umn.edu/planting-and-growing-guides/protecting-trees-and-shrubs-winter#sunscald-1263860

The branches probably are affected by anthracnose, a fungal disease. I see some brown to black spots on the leaves which look like anthracnose. Here are details on it- https://web.extension.illinois.edu/cfiv/homeowners/050519.html

The branches can also have cankers from anthracnose which can kill the branches, or some dieback due to freezing early in spring. In the following link you will find how to do a test to see if the lower branches or buds are still alive. If they are, the tree may push out a set of leaves from dormant buds, given time. https://extension.oregonstate.edu/news/how-examine-deciduous-tree-leaf-out-problems

This tree has extra stress on it because the root flare is buried. The root flare should be at soil level. https://hort.ifas.ufl.edu/woody/root-ball-dimensions.shtml

See an example picture of a root flare attached below. Pull mulch back from the trunk and carefully remove some soil to see if you can find the beginning of the flare that goes into the roots. Leave this uncovered. If the flare is too deep in the soil you should have a certified arborist out to give advice on what to do- he/she may recommend re planting the tree at the correct depth. At the same time he/she can diagnose the branches, too. Find certified arborists here-

www.treesaregood.org

These are hardy trees but this one has a bad start. By correcting these issues, and removing dead wood, I think the tree can recover.