I just upgraded to an S10+ and opened the game to find all my dragons marching out are Ruby The phone has 8GB of RAM so I don't think it should have a problem showing my dragons. I hope it will be looked at soon.
They should be adding that phone to the list of compatible phones. They have to add each phone separately to the list because some new phones don't have enough ram, but once it's added, you'll see more than just ruby. I did see one of the Devs address it on discord a while back.
Just got a Galaxy A71 5G and they are all Ruby's again. 2 years ago my s9+ was fine. How long did it take for a fix?