we have no ipv6 enabled device in our network.
I recommend doing a quick packet capture instead. Torch can be a bit ambiguous (at least to me) as to which direction the packets are actually going and who is really the source/dst of the traffic.
I set up a test ping (and dropped it on the target so the traffic would be one way).
On the sending Mikrotik, torch shows the ping-to address as the SRC, and shows activity in the TX direction....
Yet on the receiving Mikrotik, The ping-to address shows up in torch as the DST and activity in the RX direction....
Given my playing around w/ torch and one-way pings, it would appear that the host sending the traffic is fe80::4619:b7ff:fe1f:c70a and it is located somewhere on ether1.
(I know this looks backwards but from my experiments, the RX/TX rate fields are always relative to the interface being torched, and I can't decide what makes the SRC/DST addresses decide which column to go into in the display, but I found that when receiving packets, the SRC address is the actual sender's IP. (when TX packets, the SRC is actually the destination in my experiments - weird)
Like I said - you can get definitive information by doing a packet sniffer on the same interface and examining the capture file in Wireshark.