Moisture is the first thing that gets in
The air on this coast holds moisture most of the year, and the summer is the worst of it. In a lived-in house the air conditioner pulls that moisture out every single day. In a house with the power off, nothing does. It settles into drywall, carpet pad, cabinet boxes and the underside of the roof deck. Mold does not need a leak to start, only still damp air and something to feed on. By the time somebody opens the front door, the smell is in everything soft in the house, and the fix is not a cleaning crew. It is tearing out and replacing the material that absorbed it.
The leak nobody is there to see
A roof leak in an occupied house gets found the day it starts, because somebody hears it. In an empty house it runs for a season. Water tracks down inside a wall, rots the sheathing and the framing, and the first visible sign is a ceiling on the floor. Plumbing is the same story. A supply line lets go during a January freeze and runs until a neighbor notices water standing in the yard. The repair for the leak itself is small. The repair for four months of that leak is a room, and sometimes the floor system under it. Nothing about this requires you to have done anything wrong.
Empty houses get visited
Tall grass, a full mailbox and no car in the drive tell everybody on the street that a house is empty. What follows is predictable. Copper pulled out of the walls, the line set cut off the outside air conditioning unit, the water heater gone, appliances gone, sometimes the wiring stripped out of the panel. Copper theft is the common one because it is fast and it pays the same day. Squatters are rarer and far more expensive, because removing somebody from a house you own is a court process, not a phone call. Boarding windows helps a little. A house that is not empty helps a great deal more.
Insurance is where this gets expensive quietly
Read your own policy, or call your agent this week and ask the direct question: how long can this house be vacant before my coverage changes. Most standard homeowners policies limit or exclude coverage once a house has been unoccupied for a set period, commonly thirty or sixty days, and vandalism, theft, glass and water damage are usually the first things to go. A carrier can also simply decline to renew you. Vacant property coverage exists, but it costs more and it covers less. On this coast, where wind and hail are already the expensive part of the premium, an uninsured empty house is what turns a slow problem into a total loss.
The city notices before you do
Gulfport, Biloxi, Pascagoula, Moss Point and the smaller towns all have ordinances covering tall grass, weeds, debris and derelict structures. The process is much the same in each of them. A notice goes to the address on the tax roll, a deadline passes, the city has the lot cut or the debris hauled, and the cost is billed against the property. Unpaid, that becomes a lien that has to be settled out of any future sale. If a structure is far enough gone, code enforcement can move toward condemnation and demolition, and a demolition bill is a lien too. None of this reaches you if the tax roll still carries an address you moved away from.
Waiting does not make it worth more
There is no version of this where an empty house improves on its own. Every month it sits you pay taxes, insurance if you still have any, mowing, and often a minimum utility bill, while the condition goes down at the same time. Money out and value down, together. That is not a reason to panic and it is not a reason to take the first number anybody puts in front of you. It is a reason to make a decision, whichever decision it turns out to be. Fix it, rent it, sell it, or hand it to a family member who will actually live in it. Any of the four beats another year of empty.