From this thread: https://www.lfs.net/forum/post/1897951#post1897951

It seems that the insim camera packets always have Roll=0
Setting camera-roll seems to work (for example with LFS-Record) but reading camera-roll does not.

Test with Insim Sniffer:

The camera is rolled to side but the packet reads R=0
Correct Roll-value would be useful for more accurate saving&loading of cameras.