R5 did not transfer video files over WiFi

I have been using ftp transfer from my R5 to my Mac. Today I noticed it skipped 3 video files. But they were marked as transferred! So I had to force it to transfer the video files. But I know it worked in the past. I remember disabling sleep mode of sorts after I found my battery drained while the camera was powered off. Not sure if that is the reason why it goes into sleep mode before the ftp transfer has completed. So I had to wake up the camera by touching a button so it would finish transferring all the files. I wonder it had something to do with that (still no excuse, but maybe more likely to encounter the bug). I wondered if anybody else noticed this.