My bitcoin node is receiving connections from

2a00:1398:4:2a00::a1
2a00:1398:4:2a00::a5
2001:0:4137:9e76:2877:25aa:51c2

on port 8333

I dont understand how I am receiving this connections because I have port 8333 closed in my ADSL router.
I have tested from https://bitnodes.21.co/ to check my node and it says it is not available, which is correct as I say the port is closed in the router.

So, how can my node be reachable by those addresses at port 8333 ? May be because IPv6 and an error in my router ?

PS: in case it helps: user-agent for that connections is Satoshi:0.9.99