Should I sue my property manager over a deposit dispute in Malaga?
A deposit dispute with your property manager is a civil contract matter, not a guest-registration one, so it sits outside what this site can tell you. A Spanish lawyer who works in property or civil disputes is the right place to take it.
This site covers Spanish guest registration and the compliance around it — SES.Hospedajes, Real Decreto 933/2021, digital certificates. A deposit dispute with a property manager is a different thing entirely: it is a matter of the contract between you and them, and of Spanish civil law.
We will not guess at it. Whether you have a claim, what it is worth and whether suing is sensible all depend on what your management agreement says, what was agreed about the deposit and what you can evidence — none of which we can see.
Take it to a Spanish lawyer who works in property or civil disputes. If cost is the concern, the local Colegio de Abogados can point you at an initial consultation, and many disputes of this kind settle long before anyone files anything.