Why is Read(Q) timestamp is not checked when a transaction issues a command reading Q?

Consider a concurrent schedule of two transactions $ T_1,T_2$ :

$ R_x(Q): T_x$ Reads $ Q$

$ W_x(Q): T_x$ Writes $ Q$

$ S:R_2(A),R_1(A),W_1(A),W_2(A)$ , this schedule is not conflict serializable.However, if we follow timestamping protocol, where $ TS(T_1)<TS(T_2)$ S is allowed because $ T_1$ can read a variable after $ T_2$ has read it, which is not conflict equivalent to schedule $ T_1 T_2$ and is contradictory to the fact that timestamping protocol gives a conflict serializable schedule. What am I missing here?