If you are the only one having this issue (first time I have heard of it, and have not experienced it) I would call it a technical difficulty. From there, knowing nothing at all, I would say it could be one of the following...
1) need to update java & browser and so on for your platform? (likely)
2) could have a hardware problem with your mouse or similar device? (likely)
3) could have malware. Highly unlikely, but I have seen some that click for you (trying to hit ads on the page).
4) other hardware problems (ram going bad, possibly, as a prime candidate) (Highly unlikely).
5) using a non-PC platform to play (?) that is slightly incompatible? Or an obscure browser that is incompatible? Etc? (very likely).
Any details can help... OS/Platform/browser as a start.
Frequently, two or three moves into a live game, a second game will begin and become the active game. I can select the other game and ignore it, and it will automatically abort. In some cases, though, bad timing will cause me to move in it when I thought that I was moving in the other.
Now I'm playing two games at once, which was not my plan.
This morning after a game, I did not send another seek, but left my computer for a bit. When I returned, my screen showed that another game had begun and been aborted.
How do games begin when I have neither accepted a seek nor offered one?