Ever experienced the red “unable to takeoff” sign change to an orange “takeoff with caution” text when you fiddle around with the shutter speed?
I have.
Without fault, if in a subdued environment, I’m able to launch after cranking up the shutter to 1/2000.
I can even lower the speed to the normal 1/50 before starting the rotors.
The behavior doesn’t make sense and I don’t complain but am a bit curious over the fact.

Hi there. Thank you for reaching out and we do apologize for the trouble. Do not use the aircraft in a poorly lit environment without GPS signals (such as at night or in a dark indoor corner). The aircraft may drift when flying or may not hover when flying in these environments. It is recommended to use the aircraft in a well-lit environment with strong GPS signals. Thank you for your understanding.

The behaviour is nothing to do with the camera. The behaviour relates to the amount of light that the drone thinks will be available for the VPS sensors. As such it makes perfect sense.
There is no need to mess with the shutter speed, BTW ''1/2000''th would reduce the amount of light reaching the camera's sensor when compared to ''1/50''th so I don't see how that can work.
All you need to do is work your way through the various messages and acceptances that are associated with the warning i.e. touch the warning notice and then the appropriate responses and you will be able to start the drone's motors and fly the drone.
I have hundreds of indoor flights with a Mavic Mini and mini 2 and I have never changed the shutter speed. Once the drone is airborne it 'realises' that there is enough light for the VPS sensors to work and the drone flies perfectly.
If you really are taking off in poor light, be careful, even if the drone has GPS its position holding will be nowhere near as good as it is when there is enough light for the VPS to work.
If you are flying indoors with no GPS and poor lighting the drone will switch to ATTI mode and, unless you are familiar with flying in that flight mode, you will almost certainly crash it.