Your comments

I have already send you the project. I hope you can find the bug.

Thank you, but when I say the bug is the connection problem I said at the beginning.

Have you resolved the bug?

When I modify 2 signals (input) in Unity, will the 2 signals  be modified at the time in PLC?

Is there a priority in the modification of signal. For exemple, if I modify 2 signals which change a variable, will the first signal in the interface change it at the end or the second signal?

If S7 can't write the input, then how it is useful for virtual comissioning with unity and TIA?

It is normal for S7 if a sensor detect an object and the signal input will be true in Unity but in TIA it will blink?

Do you have a method to modifie the input with S7 like using a Memento?

If I want to write the input and read the output, it is better to use the interface PLCSIM advanced?

I heard from an automation specialist that it is normal to not write an input but the interface PLCSIM can do it?

I retried with the interface PLCSIM advanced and I can force a signal at true and the corresponding signal in TIA will be at true. Perhaps the interface PLCSIM advanced is better than S7 TCPIP for virtual commissioning between Unity, TIA and Wincc (HMI)?

The input forced at true is in Unity. Normally, you can force input from Unity to PLC. Even if I don't force it at true and initiate it value at true at the beginning, the corresponding signal in TIA program block just blink sometimes.