Simulink RF Blockset Error: Delay History is Too Long

Hi,

I am currently modelling an RF system using the RF blockset in Simulink. However, during simulation, I encountered the "delay history is too long" error when trying to use the "variable time delay" block to model the delay for a transmission line. The reason I am not using the "transmission line" block in RF blockset is that it is not tunable (the time delay cannot be varied during simulation).

Currently my delay is set to 1e-9 seconds, I tried values such as 1e-15 seconds but the error is still there. Interestingly, when I remove the variable attenuator and variable phase shifter, the system can simulate just fine.

Here is the error:

Here is the RF Configuration block setup:

Any help is appreciated. Thank you.

Raymond