FNIRSI 1013D tablet scope - display issue or normal behavior ?

[pfm]

Just got a 1013D and have a couple of questions on what to expect from the display. The manual is of no help in this regard.

- When the time scale is changed to 100ms/div or higher the bottom measurement panel (where it displays Vpp Vrms Freq etc...) disappears. It appears only from 50ms/div or lower. Is there anyway to lock it for high time scales as well ?
- On very small signals (~10mv) when the vertical scale is changed between 100mv/div and 50mv/div there is no difference in the size of the waveform. But on slightly larger signals even like 100mv or more it works fine. Is this a defect ? Or is there some issue related to its minimum amplitude resolution ? What adds to the suspicion is that when it is switched between 100mv/div and 50mv/div I dont hear the relay click like I hear when switching between other ranges so surely its doing something different for 50mv/div.

[Atlan]

1. switched between 100mv/div and 50mv/div
This is a software issue, data from the 100mV range is multiplied by 2

2. When the time scale is changed to 100ms/div or higher the bottom measurement panel (where it displays Vpp Vrms Freq etc...) disappears. It appears only from 50ms/div or lower. Is there anyway to lock it for high time scales as well ?
Property of the original firmware, it cannot be changed.

https://www.eevblog.com/forum/testgear/fnirsi-1013d-100mhz-tablet-oscilloscope/2150/

[pfm]

I want to correct/add one piece of information in my original post -

I said the second issue happens only for small amplitude signals. That is not true. It happens for any amplitude signal. Basically at and above 100ms/div when you switch between 100mv/div and 50mv/div there no difference in the amplitude of the displayed waveform. I would expect the waveform to double or halve based on the selection but it just stays the same. I think this is a bug in the software/firmware. Is this issue fixed in the github firmware ?

Question # 3 - what is the minimum signal this scope can detect ? Looks like it may be about 10mv ? Isn't that too high as compared to other entry level scopes ? I thought it would be around 2mv ?

[Atlan]

Sensitivity is 100mV/div. 8bit ad converter. 800mV /256 is 3,1mV per bit. Interference is 1-2bit. Maybe 2x3,1 is 6mV and more.

[pfm]

yeah by my measurement its like about Vrms 8-9mv. Below that it does not register a good stable wave or any voltage or frequency measurement value.
This for signals under 40khz only as I was using a soundcard for a test signal.