Oscilloscope displays waveform calculation period problem

You have set the scan time of the oscilloscope too long, so one grid displayed on the screen contains multiple cycles, and you cannot see the actual waveform. It can be understood that it is what you set. The scanning time has reached the resolution limit of the oscilloscope and cannot be displayed. It needs to be enlarged and the resolution increased to be suitable for naked eye observation. And you won’t be able to calculate the period accurately this way, because the unit is too large.