Is the op amp less than advertised?

Question

Electronics

I am doing the analog part for the oscilloscope described in the article .
Opamps came to me - AD826ANZ.
When choosing, I looked at the datasheet, they seemed to fit. Excerpts from the datasheet:
50 MHz Unity Gain Bandwidth
350 V/us Slew Rate
70 ns Settling Time to 0.01%

But in reality, everything turned out differently. I assembled a repeater on it

and this is what I see:

At the top is the input signal, at the bottom is the output.
The input swing is about 4.5 V.
1 division = 0.5 µs.
It turns out that the slew rate of the signal is no more than 2-3 V / μs instead of the declared 350.
What is it? Am I doing something wrong or did I read the documentation wrong?
I supply power at 7.5 V, the input signal is somewhere from 2.5 to 7 volts.

Answer 1

Can't you tell from the outside? They look like this:
I bought these .
I checked it again with another signal:
1 division = 1 µs
input signal is also 4.5 V
We got the same ~ 2V/µs

Answer 2

What oscilloscope are you looking at? To see a square wave with frequency X, the oscilloscope bandwidth must be at least 10*X.

Answer 3

On Ali, the same thing, flew by $ 13 by buying 5 pcs. AD8032 Pictures
just like yours, 2-3 V / μs.