I hope samsung adds reduce animations back (I am pretty annoyed they removed that) and I hope they make the animations more fluid if they force you to have them... remove animations is great but animations within apps are removed like loading symbols (they should disable animations only in one ui home).
I am on the same boat as you and I think others are too. I have been debating saving battery with 60Hz because of these issues. Sorry I couldn't help but I think only Samsung can unfortunately...
i think its because it's not 120hz all the time. they change refresh rate depends on situation, thats why the name for 120hz is changed to adaptive.
if you still think you have a problem with the phone, you can report the issue on samsung members app.