When firing an Update Trigger, one of the fields only refreshes after a second Update

I created a trigger to report the fine on the return delay of rented movies, however, when triggering the trigger once (giving an UPDATE), the "MultaTotal" field does not update (only it). But when the trigger is triggered a second time, the field informed is updated normally. Does anyone know how to solve it, if it is a problem, or is it something normal for the case presented?

TRIGGER:

instead of update
as

declare @CodLoc int
declare @FilmeLoc int
declare @Multa float

select @CodLoc = CodLoc, @FilmeLoc = FilmeLoc, @Multa = Atraso * MultaDia

from inserted

UPDATE Locacao
SET Atraso = DATEDIFF(DAY,DtAluguel, GETDATE()), DtEntrega = GETDATE(), Situacao = 'Devolvido', MultaDia = (SELECT MultaDia FROM Filmes WHERE CodFilme = @FilmeLoc), MultaTotal = @Multa
where CodLoc = @CodLoc

update Filmes
set Disponibilidade = 'Disponivel'
where CodFilme = @FilmeLoc

And the following table:

TABLE Locacao
(
CodLoc INT IDENTITY (1,1) NOT NULL,
ClienteLoc INT FOREIGN KEY REFERENCES Clientes(CodCliente) NOT NULL,
FilmeLoc INT FOREIGN KEY REFERENCES Filmes(CodFilme) NOT NULL,
DtAluguel DATE,
DtParaEntrega DATE,
DtEntrega DATE,
Atraso INT,
Situacao VARCHAR(9), /* Alugado ou Devolvido */
MultaDia FLOAT,
MultaTotal FLOAT,
PRIMARY KEY (CodLoc)
)

However, when I do an Update, the FullTotal field only refreshes after a second Update:

Example:

    insert into Locacao (ClienteLoc, FilmeLoc, DtAluguel, DtParaEntrega, Situacao, MultaDia)
    values (2, 1, GETDATE(), DATEADD(DAY, 3, GETDATE()), 'Alugado', 2)
    SELECT * FROM Locacao

CodLoc      ClienteLoc  FilmeLoc    DtAluguel  DtParaEntrega DtEntrega  Atraso      Situacao  MultaDia               MultaTotal
----------- ----------- ----------- ---------- ------------- ---------- ----------- --------- ---------------------- ----------------------
3           2           1           2018-12-09 2018-12-12    NULL       NULL        Alugado   2                      NULL

Update 1:

update Locacao
set DtEntrega = GETDATE()
where CodLoc = 3
SELECT * FROM Locacao

CodLoc      ClienteLoc  FilmeLoc    DtAluguel  DtParaEntrega DtEntrega  Atraso      Situacao  MultaDia               MultaTotal
----------- ----------- ----------- ---------- ------------- ---------- ----------- --------- ---------------------- ----------------------
3           2           1           2018-12-09 2018-12-12    2018-12-09 0           Devolvido 2                      NULL

Update 2:

update Locacao
set DtEntrega = GETDATE()
where CodLoc = 3
SELECT * FROM Locacao

CodLoc      ClienteLoc  FilmeLoc    DtAluguel  DtParaEntrega DtEntrega  Atraso      Situacao  MultaDia               MultaTotal
----------- ----------- ----------- ---------- ------------- ---------- ----------- --------- ---------------------- ----------------------
3           2           1           2018-12-09 2018-12-12    2018-12-09 0           Devolvido 2                       0