The service record showed the oil was changed every service. Maybe they only thought it needed reset if the light flashed. Most small garages are aware of the DPF reset requirement but they are NOT aware that it is a separate procedure to the service reset on some Fiats. Unfortunately most garages still seem to push the yearly oil change whatever the mileage. I had a big discussion with a Ford main dealer about the wife's petrol Focus last year.
Just to let you know, dpf is still working after 2 months and few 1000km, so i guess thermostat solution worked for me. Will let you know if anything change.
will write more when i will visit mechanic.