"Enable dictionary access to base workspace" flag setting sometimes gets cleared by itself

I am working with R2020b and I have a Simulink data dictionary with "Simulink Variant" objects, which use in their conditionals a variable defined in the base workspace.

Therefore I set the flag "Enable dictionary access to base workspace" for the data dictionary to see the needed MATLAB variable.

However, sometimes the flag gets cleared after opening a new MATLAB session, and I don't know why. Therefore when it happens I need to open my data dictionary and set again the flag. This seems a bug to me. Unfortunately this faulty behavior does not seem to be 100% systematic.

Thanks

Luca