Lost Pet: Elliot

Circumstances

He was playing outside on 10/16. His last known location, at around 110 pm, was outside an apartment not far from me. Then his GPS collar persisted in that location for around 30 minutes before I went to find him. It said he was inside an apartment. Outside there is a cat food bowl and toys. I placed a note on the door. Around 10 minutes later the collar moved to a windowsill across from and outside that apartment without any Elliott. I checked his usual locations and he is not there.