BF1 & BF4 lost connections to the session

This problem began to appear just several months ago for both my bf1 and bf4. When i join a server in the server list and play for about 5 to 10 minutes (bf4 might be longer, like 15 mins), i will be kicked out of the server, and it will show me the message "YOU HAVE LOST THE CONNECTION TO THE SESSION". I think my EA app is okay it's online, just cannot successfully connect to any game server. I tried to play them on another device, and the same problem came again. By the way I use WLAN and an accelerator (delay and ping are kinda high for me to play like eu server in my region).