The other settings in the ctrl+F find window are remembered for the next find, but “find in selection” is always off when find opens. Also, there doesn’t seem to be a hotkey for find in selection either.

Sublime 3 3033, Linux

[code]{ “keys”: “alt+s”], “command”: “toggle_in_selection”,
“context”: {“key”: “panel”, “operand”: “replace”}, {“key”: “panel_has_focus”}]
},

{ “keys”: “alt+s”], “command”: “toggle_in_selection”,
“context”: {“key”: “panel”, “operand”: “find”}, {“key”: “panel_has_focus”}]
},[/code]