I did not found any similar topic so i started this.
First of all a user cannot join to my home network on wifi if its device mac address is missing from the router's mac filter. I'm using WPA2 authentication with a 15 long password that contains lowercase and uppercase characters, special characters and numbers, its not even pattern-like. My router can be accessed only on a wired device.
So on my phone in spotify an Amazon FireTV (to clarify - i dont have an amazon firetv) appeared in the device list, i accidentaly pressed this and after that my computer to continue listening the music in my room.
Later my music turned off, i checked spotify and i saw in the device list that spotify is listening on Amazon FireTV. I thought it is some kind of bug so i selected my computer again, after that again silence and music continued on somebody's iphone7. This repeated like 5 times and im sure it was not my device because the user listened some trash that was kind of noise for me.
I checked my router's client list and only my computer and my phone was on it. (by interface one wired and one 2.4ghz wifi).
Then i disconnected all devices on my account management page.
But the question remains here, what was this? It sounds like some security issue, isnt it?
Solved! Go to Solution.