Partner seeing things in her sleep that are not happening, please help!

Hello. My girlfriend of three years insists that she sees me awake and using my phone in the wee hours of the night. I have never done this, my phone is face down on my bedside table and on do not disturb between midnight and 7 AM. I have even shown her my screen activity, it is frustrating to need to provide proof but here we are. And she has a history of trouble staying asleep and being woken up easily by lights and sounds. Despite this, she is absolutely certain that I am using my phone and it is starting to create major trust issues in our relationship. Has anyone else experienced this? It keeps on happening and I am unsure what else to do when we cannot agree on our shared reality. Any ideas would be so much appreciated, thank you in Advance.