Can't fill luminance value table after semi-automatic gamma calibration

OS (e.g. Win10): Win 10 Pro
PsychoPy version (e.g. 1.84.x): v.2023.2.3
Standard Standalone? (y/n) yes
What are you trying to achieve?:

After performing a semi-automatic gamma calibration, a table appears in which I can enter the luminance values recorded. The table is displayed correctly but it’s impossible to fill in a cell: as soon as I type in a number, Psychopy freezes and the following text appears:

wx._core.wxAssertionError: C++ assertion ““Assert failure”” failed at …..\src\generic\grideditors.cpp(1002) in wxGridCellFloatEditor::BeginEdit(): this cell doesn’t have float value
The above exception was the direct cause of the following exception:
SystemError: <class ‘wx._core.IdleEvent’> returned a result with an error set

First of all, I tried to type a dot to initialise the cell as a float value, but I couldn’t insert it.
I changed the monitor and the problem remained the same. I’ve tried to dig into the Monitor center and calibration scripts but so far I haven’t found anything.

Any suggestion would be useful!

Thanks in advance,

Ugo