I host an api on render for 7$ monthly and for my app it is more than enough. At the end of February I got an invoice of 124$ for bandwidth "beyond my plan", exactly 442 GB. I did not make any changes to the code since May 2024 and now all of a sudden my app uses 400 GB in a month. Upon questioning the platform what happened they showed me a breakdown of my usage and the extra 442 GB were assigned to /socket.io/. I use socket.io in my app but until now it did not cause any problems and the user base also did not increase that much in order to require this amount of bandwidth. What can be the cause of this strange bump in bandwidth?

I tried to search for an explanation online but could not find anything relevant to socket.io and excesive bandwidth out of nowhere.