Silk ivory lilac help

Hello all, I am a novice looking for help. My silk Ivory lilac is about 4 years old. This summer, one branch didn't bud fully (first photo). Additionally, another branch grew some new stems and leaves, but those leaves are now curling and becoming brown at the tips (second photo).

The start of June was quite dry, however, we were watering new sod regularly and the tree was getting some water from the sprinkler.

Thanks!