I have a completely repeatable glitch that happens several times a day.
We have a mirror which refuses to reflect me!
It’s a full length mirror mounted on the wall of our large square hallway opposite the kitchen door, so I pass it several times per day. If reflects everyone else, just not me.
We have come to the conclusion that maybe the mirror is slightly concave, and I am a few inches shorter than other family members, so must be a trick of how the light reflects/refracts.
If I stand in the kitchen doorway you can see the doorway and the room behind me, but not me. I don’t appear in the mirror at all until I have walked diagonally across the hall, and then you can see me just disappear from the edge of the mirror.
It is all completely repeatable, so we have experimented with it. We have tried having my husband or son stand exactly in my place (they are visible standing in the spot where I wasn’t), having one of them stand directly behind me (they are fully visible, I am not).
It’s a long running source of amusement now, primarily because the mirror was inherited from DH’s grandmother, who disapproved of me. So we joke that maybe she is passive-aggressive ignoring me from beyond the grave
(but seriously, if must just be a combination of my height with a flaw in the mirrors surface).