That appears to be dht nodes you are connected to. This is normal overhead when sending info back and forth, if you want to avoid it you can disable DHT but you will lose the advantages the technology offers.
There is also some bandwidth used when you connect to cometID and when your port is checked but this is usually lowers to nearly 0 after a few mins of usage, but the DHT will continue to receive connections that are inbound even if no tasks are running. In some cases you will also receive traditional bittorrent connections up to an hour after a task is stopped and in some rare cases much longer.
I have used bitcomet with DHT activated for several years now. I am used to keep bitcomet running on the background even through i am not downloading anything and had never seen something like this.
Even if i restart my pc, the traffic will resume as soon as I relaunch bitcomet and won’t stop no matter how long i wait.