This might be a feature of new pathing instead of bug. Hopper runs to midpoint of units and can't choose where to go. Similar thing happens with other units too, fighters included.
Build:
{"Towers":[{"T":"treant_unit_id","X":-2.0,"Z":-3.0,"S":2.0},{"T":"golden_buckler_unit_id","X":4.0,"Z":-3.0,"S":0.0},{"T":"sea_serpent_unit_id","X":-2.0,"Z":6.5,"S":0.0},{"T":"peewee_unit_id","X":3.0,"Z":-3.5,"S":0.0}],"Rolls":[],"LegionSpellPositionX":-5.5,"LegionSpellPositionZ":-8.0,"ChampionX":-5.5,"ChampionZ":-8.0,"Gold":0,"Mythium":60,"Wave":3,"LegionSpell":"","ExtraRecommendedValue":0,"HorizontalPref":0,"VerticalPref":0}
Send was DT and Snail.