If you are near the coast and your property got a big salt water surge there could be an issue with residual salinity. If so, just water adequately to dilute and leach the salts. But if that's not it, the decline and poor health could be unrelated to Maria last year.
From what I see in the photo, the problem may be related to the poor growing conditions. There appears to be very limited planter space, with gravel covering the soil, and maybe plastic under the gravel. And it's on the edge of a lawn area. These factors make it difficult to provide good soil and water management. Grass takes a lot of water and fertilizer and the demands can be competitive with the needs of the palm. You need to water and fertilize to provide enough for both.
It's hard to water adequately with the restricted area in the small planter, and especially if the soil surface is covered with plastic and rock.
Without knowing more about your maintenance, watering and fertilizing, I would guess that you could improve the conditions by removing the plastic and rock, and use an organic mulch in the planter instead. Fertilize with a palm fertilizer, or general purpose tree and shrub fertilizer. Water adequately; drench the planter once a week if not more often.
The other extreme is if it is getting too much water, but that does not appear to be the case from what I see.