If you can, try replacing - temporarily - in /routing rule the action=lookup with action=lookup-only-in-table and see if it makes a difference.
But is this the “real world” or a lab simulation?
If the latter, do you have really three devices with 10.100.50.43, 15 and 49?
If it is simulated by a single device with an ethernet port with multiple IP addresses, it often happens that one among the addresses is chosen and shown in trace, I seem to remember that usually it is the “lowest” one (i.e. an interface with 10.0.0.1 and 192.168.0.1 is shown in trace as 10.0.0.1) but it may be different on different routers and/or ROS versions.