Riding a named horse, dismounted to pick a flower and the horse was gone. Spent time looking for the horse, was not able to find it. Tamed another horse in the area, put a lead on another, began heading home. At some point the lead snapped, I went back to get it. Upon dismounting, again the horse disappeared. I then tamed the third horse, rode it home to spawn area, but that one didnt disappear.

Searched for known bugs, found similar resolved/duplicate issues, said reloading the game worked to bring them back. Tried that, was able to locate the second horse, but the first (named) horse is still nowhere to be found. Went into spectator mode to go below the ground, to make it easier to find the horse on land, with expanding radius, but horse is still gone.