A. 1. Open the Google Calendar app and tap on the three horizontal lines in the top left corner. 2. Scroll down to 'Settings' and select your account. 3. Ensure that 'Sync' is enabled. 4. If it is enabled, try toggling it off and then back on. 5. Check your internet connection to ensure you are connected to Wi-Fi or mobile data.
B. 1. Go to 'Settings' on your device, then 'Accounts' > 'Google' > select your account. 2. Ensure that 'Calendar' is checked for syncing. 3. If syncing is still not working, remove your Google account and then re-add it: 'Settings' > 'Accounts' > 'Google' > select your account > 'Remove account'. After that, add it back.