I am trying to make a smooth camera movement around the car via inSim, but when I send ISS_SHIFTU_FOLLOW flag it doesn't work (without follow flag, camera works fine).

As docs say:

Quote :

// If the requested camera mode is different from the one LFS is already in, it cannot
// move smoothly to the new position, so in this case the "Time" value is ignored.

But it's still the same camera mode, the same flags, so I don't know what is going on. I am using LFS_External, but it doesn't matter I think. How to solve this? If there is a way to do this.

Might be because it's following a moving target, so I'll check and advise when I get up to that packet.