If you use some app such as Network Survey (open source, Android), you can see that providers also lie about the type of connection. I'm on LTE now, but provider makes phone display 5G.

And this is on non-provider phone, this is built in in the whatever communication they do with the phone, possibly works with every device.

Thank T-Mobile crying to the ITU-R to get 4G and 5G technologies renamed so they could peddle bullshit marketing.

Man, I love my HSPA+ “4G”!

Technically not lying if this is NSA (non-standalone) 5G. The 5G band just comes on as an additional aggregated band. The icon just shows up because the tower is capable of supplying the band.

Really the bigger problem is that there's not enough distinction between SA and NSA