Slew rate and Bandwidth for 5 MHz signal

I'm trying to amplify a sine wave signal with opamps of high bandwidth and slew rate. It works fine up to about 700 kHz, then the gain decreases and about 1 MHz it's only 1, when it should be about 5.

I'm testing with the circuit below and two different opamps, with similar results: LMH6658 (bandwidth 270 MHz, slew rate 700 V/μs) and AD8066 (bandwidth 145 MHz, slew rate 180 V/μs).

LMH6658: https://www.ti.com/lit/ds/symlink/lmh6658.pdf?ts=1711450406602

AD8066: https://www.analog.com/media/en/technical-documentation/data-sheets/ad8065_8066.pdf

I don't know if I miss something. Should I expect to be able to get a gain of 5 with these opamps up to 5 MHz?
I'm testing in a breadboard. The input signal is about 600 mV, and the sine wave is clean and not distorted in the output, even above 1 MHz.

Could be that the opamps are fake/relabeled, but before returning and ordering them in Mouser I wanted to make sure. I don't know if there could be other problems. I understand that the opamps with that bandwidth and slew rate should be enough for these frequencies, but I'm not sure.Thanks!

Edit: I add some concrete numbers. Checking it better I see the performance of both opamps is different (after many tests I had a mix of results in my head). LMH6658 is much better, but anyway the gain starts to decrease below 500KHz.

LMH6658 (input signal ampl -> output signal):    100KHz: 680mV -> 3.32V    400KHz: 680mV -> 3.24V    600KHz: 680mV -> 3.16V    800KHz: 640mV -> 3.00V    1MHz:   600mV -> 2.84V    2MHz:   480mV -> 2.16VAD8066:    100KHz: 680mV -> 2.56V    600KHz: 680mV -> 1.30V    800KHz: 640mV -> 1.00V    1MHz:   600mV -> 760mV    2MHz:   480mV -> 360mV