The below method is not mentioned any of the google support articles and also not known to many users. The one-word answer is “4G/LTE -> 3G” data connection.
By changing your Network Mode from 4G/LTE to 3G the download or updates not happening in your google play store will start happening.
Also, don’t forget to change the settings of Google play store to load from Mobile Data instead of Wi-Fi alone.
NOTE:
Unstable high-speed data is the cause of this problem.
Why Surf Swim 