I was with last update . After update was worse than before.I tryed the suggestion with airplane mode.From Lenovo support sent to me instruction for hard reset. The result is nothing. I still have the same problem.
I have Lenovo tab 4 8" plus .
Wi-Fi 802.11 a/b/g/n/ac, dual-band, WiFi Direct, hotspot.
This is the model:
https://m.gsmarena.com/lenovo_tab_4_8_plus-8603.php
I found more people with the same problem