An additional request was reported concerning a French Schengen visa used to enter Spain and then apply for residence. The applicant had to show that France really was the main destination of the trip.
The applicant entered the Schengen Area through France, then visited Belgium and arrived in Spain to file the residence application. During the Spanish review, a request asked them to explain the route and evidence actual stay in France as the main destination.
In this case, the authority issued a request rather than an immediate refusal.
Practical takeaway: when using another Schengen country’s visa, respect the conditions under which it was issued and keep evidence of the real route — bookings, transport documents and proof of stay. A few days in the country of entry do not by themselves prove it was the main purpose of the trip.