I have a S9 phone for several years and it's one the best phones that I owned Recently I encounter a strange annoying issue, I use whatsapp web with my phone next to me and in many cases after the phone enters into screen lock, I get error message saying that my phone doesn't have an internet connection 😞 when I unlock my phone and open whatsapp, the error message on my laptop disappears I don't move my phone during that time and my laptop is using the same wifi connection without any problems
Hi are you using WhatsApp Web for the convince off typing, As you have it on your phone am not sure why u using both. Try this Restart your phone, by turning it off and back on. Update WhatsApp to the latest version available on the Google Play Store. Open your phone's Settings > tap Network & internet > turn Airplane mode on and off. Open your phone's Settings > tap Network & internet > Data usage > turn Mobile data on. Open your phone's Settings > tap Apps & notifications > WhatsApp > Data usage > turn Background data on. Open your phone's Settings > Network & internet > Wi-Fi > turn Wi-Fi off and on.
Make sure Wi-Fi stays on during sleep mode. Reboot your Wi-Fi router. Turn off roaming.