effective sample rate vs open_bci LSL sample rate

[JARS29]

Hi! I am using LSL for recording my data from the OpenBCI. I am running using cmd command (--stream). It is supposed, based on open bci's documentation, that the sampling rate is 250hz by default. Running as in the example, I obtain this picture where the rate showed is 125hz:

I went into the code for trying to identify where this set up comes and I found this division:
https://github.com/OpenBCI/OpenBCI_LSL/blob/3134a1513c204834d66084491f104e6f236e440b/lib/open_bci_v3.py#L117

Why is the sample rate divided by 2? When I remove this, my new setup in the cmd is:

Despite this change and set up the sample rate using the SDK into LSL (employing the command ~), the sample rate remains the same. For demonstrating it, I recorded the data (using labstreamlayer recorder) and opened the XDF file in Matlab I just realized that the effective sample rate remains 125hz, as Matlab highlights:

I also calculated the diff between time stamps and effectively I obtained 125hz (0.0080).

Can someone explain how I really can set up the sample rate for an effective sample rate (>250Hz) for recording through LSL.

Thanks!