@Kirsty10Have you installed any apps recently or done a software update? If so try and remove the application that you last installed.
Your only other option is to Factory Reset your iPhone, which will clear ALL Data from the device, so ensure you have an update.
If this doesnt solve the issues, then it could be a device fault, so I would suggest speaking to Apple Support @
https://support.apple.com
- Xperia 1V - o2 and Spusu
- Pixel 8 Pro - o2 and Vodafone UK