Should be asking whether is the test done with a phone having n40 5G band. Simba 5G uses n1, n38 and n40 bands, but only the n40 has the big bandwidth. Simba themselves mentioned must configure to use their n40 band, so even if a phone got 5G signal doesn't mean it is connected to the n40 band. Those phones with China ROM usually don't have this n40 band. I nearly wanted to buy a new phone with China ROM, but after reading up, I think I won't be getting good speed without the n40 band.
That's not all, the best 5G speed rides on mmwave, some chipset has it, some don't. Like the Redmi note 12 Pro using Dimensity 1080 chip, it has mmwave, but come to the new Redmi note 13 Pro using Dimesntiy 7200, that chip don't have mmwave even though it is a newer version.