Bug/Issue [Dedicated server] Multiple connections from different sources?

I don't know how to explain this problem, because it has never happened to me before and doesn't seem normal.

The thing is that the dedicated server console reports multiple connection attempts by different IPs to the server, and failing because it can't uncompress data or something like that.
Also, sometimes clients cannot connect to my server - I have successfully opened the ports and people can join, but rarely happens that the server is unreachable for no particular reason. I don't think it has something to do with this problem, but I thought I could mention it anyways.

My console is being plagued with this (IPs blurred):

It happens anytime while the server is open.

Should I be worrying about this?

EDIT: I somehow managed to go past what should I include in this post, so here goes:
I'm using Windows 10 64 bit. I'm only using non-gameplay modifying mods (attached).