I was gifted this lemon tree 2 years ago. I transplanted it to larger pot this spring since I have finally moved to a house ( instead of a condo ). The tree did have quite a few flowers earlier this month, but now there is no evidence of any type of fruit forming , some leaves are mottled ,some are curled and some branches have spaces where it appears that leaves were there but now there are just bumps were leaves seem to have broken off at their attachment to the branch. I have seen no insects or larvae and am in a quandary as to what the problem may be. I know what deer damage looks like and the missing leaves do not seem to fall under the deer munching category.
This tree is in zone 8b

The curled leaves could be leaf miners which do not really harm the plant, but make the leaves ugly. The rest of its woes may just be transplant shock. I would not be too concerned at this point.