Rate transition inside function call subsystem

Dear,

I try to run a multi rate model using function call subsystems.

However, I get following error:

'MasterModel/FastTask/Ctl/M1/Speed/AT_FirstOrderFilter_Reset/AT_DiscreteTimeIntegrator_Backward_Reset/AT_ResetMethod/AT_Ground/Rate Transition' is a rate transition block. A rate transition block is not allowed inside the function call subsystem 'MasterModel/FastTask' unless its input or output port sample time is asynchronous sample time. Consider placing the rate transition block outside the function call subsystem.

Since the rate transition block in the function call subsystem is part of a large custom simulink library, I cannot just remove it or put elsewhere.

How could I resolve this issue?

Kind regards,

Niels