/clear when a map opens in another inventory slot will cause glitched map

The bug

If you have two maps in one slot, and you open one of them, the filled map will be put in another inventory slot. But if you set a clock clearing all filled maps, the map which opens in another slot will be glitched out.
The glitched map got these properties:

• In creative, the map can be moved around in your inventory, but can't be cleared with commands.
• If moved around in inventory, the /clear command will trigger, giving the output that it cleared 1 item from you, but the glitched map is still there
• In survival, if you try to move around the map, it will disappear
• If you drop the map, it will instantly disappear

How to reproduce

1. Put down a command block
2. Set it to repeat, always active, and use this command:

   clear @a filled_map
   

1. Then, give yourself 2 maps and put them in the same hotbar slot
2. Activate one of the maps
3. The activated map is glitched out

Please watch this video for a demonstration.