A.I. & Stealth & Battle: Going stealth should not make the A.I. totally lose track of your last location and pass on their turn.
Fix Idea; If all the A.I. enemies lose sight of the attackers, the A.I. should use Dash in an attempt to close in on the last known location and expose as many party members as possible. Meaning the A.I. will use all it’s movement to get as close to the stealth party member as possible.
Easy Fix; If the entire party is stealth and a determined distance from enemies, let the enemies reset to include healing to full.
I believe this is a partially implemented mechanic already. When you Hide in combat, a little pillar of light is left behind where your character used Hide. Currently, this does nothing. Logically, one assumes the AI will investigate this location if the character that disappeared from that area does not reemerge within their line of sight.