Disconnection problem

Hi all, I am having a connection/disconnection trouble for more than a month, and I realized the problem is independent from my sketch. I thought there was something wrong with my code till I use simple sketches from blynk library.After i get connected to the blynk it’s disconnect and try to connect again.
During this time apps says “Device was disconnected” and “Device is offline”.
When i press some buttons on the app,it disconnects immediately.

Here is my serial output:

[3247] Connected to WiFi
[3248] IP: 192.168.1.8
[3248] 
    ___  __          __
   / _ )/ /_ _____  / /__
  / _  / / // / _ \/  '_/
 /____/_/\_, /_//_/_/\_\
        /___/ v0.4.3 on NodeMCU

[5001] Connecting to blynk-cloud.com:8442
[5538] Ready (ping: 0ms).
[10539] Connecting to blynk-cloud.com:8442
[11182] Ready (ping: 0ms).
[20647] Connecting to blynk-cloud.com:8442
[21215] Ready (ping: 1ms).
[26218] Login timeout
[26219] Connecting to blynk-cloud.com:8442
[26850] Ready (ping: 1ms).
[32160] Login timeout
[32160] Connecting to blynk-cloud.com:8442
[32692] Ready (ping: 2ms).
[50307] Login timeout
[50308] Connecting to blynk-cloud.com:8442
[51017] Ready (ping: 1ms).
[56021] Login timeout
[56021] Connecting to blynk-cloud.com:8442
[56559] Ready (ping: 2ms).
[64315] Login timeout
[64315] Connecting to blynk-cloud.com:8442
[64908] Ready (ping: 2ms).
[80394] Login timeout
[80395] Connecting to blynk-cloud.com:8442
[80954] Ready (ping: 2ms).
[87340] Login timeout
[87341] Connecting to blynk-cloud.com:8442
[87983] Ready (ping: 1ms).

Blynk Android 2.1.0
Samsung Galaxy Note 5

Good first step, so it’s probably not the sketch. Have you tried different hardware? Do you connect with wifi? Because that could be the culprit too.

I have just nodemcu board,but when i switch to local server it works without any issue. Generally i use blynk with http requests via browser or shortcuts.