@Tomokokuroki: To enter Safe mode, press and hold the Side button until the 'Power off' prompt appears on the screen then release > Touch and hold Power off until the 'Safe mode' prompt appears then release > To confirm, tap Safe mode.
With Safe mode active, monitor the performance of the device for a few hours, based on the frequency that you encounter the issue. If you find that Wi-Fi maintains its connectivity, then please restart your A14 as you would normally and uninstall any apps that you have added to the device since you first encountered the issue. It won't be possible to determine exactly which app is at fault, therefore I recommend approaching this via a process of elimination.
@Tomokokuroki: If your issue persisted while Safe mode was active then I recommend arranging for the phone to be inspected by an authorised Samsung engineer, who can get to the root of the problem for you. To do so, head to samsung.com > Scroll to the bottom of the screen > Contact us > Get in touch with our Support Team via your preferred contact method, and an advisor will be on hand to assist you further. Alternatively, head to the Samsung Members app > Support > Repair service > Find a service centre.
Before you go ahead, if you have not already done so, I recommend backing up your data and performing a factory data reset. This will return the phone to it's default factory settings, and may resolve the issue without the need for an inspection. For a guide on how to proceed, please click on the link below.
