Again, mine have always done that too.
Some thing to remember is that while it might be easy to think about Atmos being about overhead sounds, it’s not that simple.
In the same way that all the speakers in a normal layout phantom image between pairs of speakers horizontally and creates smooth panning around the room, Atmos does the same thing but it also does so between the ear level “bed” speakers and the height/top speakers. This creates the 3D effect and allows for XYZ coordinate placement. I’ve seen where people will say to watch a movie with only the top/height speakers active and see what they’re doing. That’s fine, but it doesn’t give the whole story. Just like watching a film with only the LCR, or only the surrounds active. Doesn’t tell you everything. It’s how they work TOGETHER!
Also, I know you watch a lot of older films. DSU and DTSnx do a great job of upmixing legacy material. So you can always get a good experience. I know you’re concerned with the new upmixers improperly navigating sounds from older tracks but it’s not something to worry about IMO. Hell, even wheel of fortune sounds good upmixed!
So while in your case you might get sound “on the ceiling” it won’t be IN the room. Keep in mind too, not all material takes advantage of this. But there are some that do, and music in Atmos can be INSANE!!!
To the question about adding rear surrounds, I don’t know. I would rather see you try to add a pair of bed layer surrounds and try to use the current IC speakers as tops. Even if they’re behind and not just in front.