Horsearmor can be copied

1.tame a horse

2.put horsearmor and a saddle in horse's inventory

3.ride it

4.kill it with a critical hit(you must ride it before the final hit or it won't drop two horsearmors)

This bug does not always happen,try some times and it will happen.

This bug also occurs in BE 1.16.220/1.16.221/1.17.0/1.17.2.