When focused in Minecraft, then alt tabbing, moving the mouse, and alt tabbing back, opening an inventory or menu will not re-center the mouse. This only occurs with pause on lost focus disabled.
To Reproduce:
0. Disable pause on lost focus with F3+P
1. Alt-tab away from Minecraft
2. Move the mouse
3. Alt-tab back to Minecraft
4. Open the pause menu
5. Notice the mouse is not re-centered but still at the place it was left at
hmm ... alt+tabbing ingame simply opens the pause menu for me. so i cannot reproduce this, or is there anything i'm doing wrong? i have attached i video of my process