OnePlus devices run a customized version of Android called OxygenOS. This system uses very aggressive battery optimization filters and non-standard gesture controls that can block background synchronization, freeze your calendar widgets, or disrupt multitouch actions inside apps. Here is how to fix these common issues.

1

Fix Widget & Sync Issues (Battery Optimization)

If your calendar widgets stop refreshing automatically, or if new events do not download until you open the app, OxygenOS is forcing aCalendar into a background sleep mode:

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Allow Background Activity

Open your phone's main Settings → Battery → More settings → App battery management. Find aCalendar in the list and select Allow background activity. (On some OS versions, search for "Battery optimization" in settings, select aCalendar, and set it to "Don't optimize").

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Disable Sleep Standby Optimization

Some OnePlus models shut down background features overnight very aggressively. Go to Settings → Battery → Advanced settings (or Sleep standby optimization) and toggle this feature OFF.

2

Synchronization Blocked by Full Storage

If aCalendar refuses to update appointments despite correct power settings, the issue is often caused by a lack of free system memory:

The Storage Rule: OxygenOS will completely stop automated background cloud synchronization for Google or Microsoft accounts when your phone runs low on disk space. Make sure you keep at least 10% of internal storage free so Android can release the system sync locks.

3

Three-Finger Tap or BACK-Gesture Not Working

If the BACK-Gesture or three-finger tap do not work in aCalendar, a known OnePlus Firmware-Upgrade bug is blocking gestures:

How to fix it: Go to Settings > System Navigation. Temporarily switch your navigation from Buttons to Gestures. Look for a setting that appears called "Swipe animations (beta)" or "Predictive back animations". Toggle it ON (if it's already on, toggle it off and back on). Switch your navigation back to Buttons. Restart your phone.