Game mode: [Singleplayer]
Region: [Anywhere under water]
Swimming under water and picking plants by hand, or with a tool (or rocks with pick/axe, etc) causes the upper body to stand upright doing the pick or weapon swing animation, and the bottom half to remain prone in the flat swimming animation. The lower back/butt part goes wonky.
Also if you resume swimming after using a tool, the tool goes unattached from the right hand but animates with the swimming animation but on your left side, completely unattached from your hand. Swimming should hide the tool, or at least keep it in your hand.
Steps on how to reproduce issue: