When loading a save state from the F12 menu, Hatari does not reset the
mouse pointer as it does when leaving the F12 menu normally. This
causes the host mouse cursor to become visible and not be aligned
properly with the emulated mouse, potentially rendering large segments
of the emulated screen inaccessible.
Entering mouse lock mode forces the host cursor to remain within the
Hatari window, but does not solve the underlying problem: the host
cursor will still be visible and desynchronized from the emulated
cursor. Entering fullscreen mode has similar effects.
To fix this issue, the mouse must be returned to non-menu mode when
loading a save state from the menu. Additionally, it would be
advisable to re-hide the host cursor when entering mouse lock or
fullscreen mode, and to prevent the host cursor from reaching the
window edge in mouse lock and fullscreen modes so that it can continue
to move even if it loses its alignment with the emulated cursor.
-FunnyMan3595 (Charlie Nolan)