Thanks for contacting us. May I ask what launcher you adopt now, default launcher or any 3rd party launcher?
1. please check double tap setting, Setting/ Gestures/ Double tap screen;
2. if you adopts 3rd party launcher, please uninstall the launcher;
3. if the problem appears again, you could try factory reset, Setting/ Backup & reset/ Factory data reset;
And we are wondering whether the screen is working properly or not, if the solutions above don't solve the problem, it could be hardware issue and then please bring the phone to service center. Please let us know the feedback. Thank you.