Gifting a unit to a city state takes 3 turns to arrive at the city state. The game seems to only keep this information in the running copy and doesn't store it into the save files. If you save during the 3 turn window and re-load the game, the gifted unit never appears.
I noticed this primarily due to the game crashing/hanging on a huge map frequently as I had to start saving very frequently. It's made gifting units quite painful and makes batch gifting quite useful (reloading to a save file prior to the gifting if the game is unable to make it 3 turns without hanging).
I noticed this primarily due to the game crashing/hanging on a huge map frequently as I had to start saving very frequently. It's made gifting units quite painful and makes batch gifting quite useful (reloading to a save file prior to the gifting if the game is unable to make it 3 turns without hanging).