I have now had this this FL for six months, and in that time the ecomode has never worked. Just returned from
France, and in Dunkirk it started working normal! Stopped to ask the local Gendrmerie where I was (always getting lost ) and it has not worked since. Is it faulty?? 2013 Dynamic Santorini black
2011 XS Lago grey
2007 HLS Stornoway grey
sometimes towing an Elldis AVANTE 574.

I think you need a new battery. Basically if the battery always requires charging then the fl won't go into eco mode.

Im assuming by ecomode you mean the stop/start

Ive had similar things on courtesy cars ive had in the past, you have to perform certain actions every time you use it in order for it to activate.
i.e. come to a stop using the footbrake, keep foot on pedals, apply handbrake, remove foot from brake pedal, knock into neutral, remove foot from clutch........... or something like that.

If you don't follow the set procedure for stopping and activating then the stop/start wont kick in. and IMO its mostly a manufacturer fiddle to lower emissions. useful in London traffic, useless anywhere else.

Other than that, as has already been stated, the battery might need replacing (there are threads all over this forum about stop/start batteries)

From the handbook:

To aid fuel efficiency, the engine will automatically switch
off when the vehicle comes to a stop, neutral is selected
and the clutch is fully released. The engine will start again
when the clutch is pressed.

Operating note
When the vehicle comes to a stop, ensure that your
feet do not touch the clutch or accelerator pedals.
Inadvertent pressure will prevent the engine from
stopping. No Longer the owner of a 2013MY Fuji White GS

"Fiat Lux" a philosophy not a car

Surely I would have used the correct method of stopping in the last six months? It worked correctly on about
twelve occasions in Dunkirk. Since then, nothing. I had just done over 500 miles that day, towing the caravan, so
I would not expect it to be the battery. One of those mysteries!  2013 Dynamic Santorini black
2011 XS Lago grey
2007 HLS Stornoway grey
sometimes towing an Elldis AVANTE 574.