I have 3 Solutions for your question :

First solution: reboot or soft reboot

Soft reset or a simple reset on your iPhone can do many good things when it comes to minor glitches. It is the first recommended procedure for troubleshooting random devices.

Second solution: exit all background applications :

Keeping apps running in the phone background offers an advantage when it comes to multitasking and reloading the same apps; there always comes a time when any of these background apps gets corrupted and crashed. If this thing happens, there is a tendency for your other applications or system functions to be affected. And that's when the apps go fake, or your iPhone misbehaves. For confirming this is not the root cause of the problem, try ending all your background apps. Doing so will also erase some space on your iPhone's internal memory, improving speed and overall performance.

Third solution: update the apps and iOS to the latest version available :

Software updates are designed to keep a device's system optimized or for applications to perform at their best. Apart from the new features, the updates also contain bug fixes to fix existing bugs that affect specific applications or the device itself. Many people were able to resolve software problems by installing software updates, so it doesn't hurt to give a try. To get started, check to see if there are updates available to install, either for your apps or for iOS.