Hotpoint FFA70 dripping from front bottom corner

Hello,
I have a Hotpoint FFA70 (same as FFS70 but silver not white), and in recent months the “Food defrost alert” light has come on multiple times, but gone off again a few hours later. The unit is 4 years old.

This morning we noticed that there are drops of what is presumably water dripping from the front right part of the cabinet. There is no apparent wetness on the door seals and no water in the lower freezer section that could be the cause.
Checking the upper fridge unit, there are some droplets on the back wall, and some drips in the inner wall drip catch, but the drain pipe appears clear, and checking the drip tray above the condenser shows that there is hardly any wetness in there. We have not moved the unit recently and usage has been the same as over the last 4 years.

I’m therefore at a loss to figure out where this water is coming from – we’re talking enough drips to make a small puddle the size of a fist in only a few hours.
It looks like the water is emerging from the very edge of the cabinet, where the metal exterior meets the interior plastic lining that forms the whole freezer cabinet. I also notice that it’s emerging around what looks like a tiny bit of yellow foam – the foam is about the size of the tip of a pencil, so only a tiny bit is visible.

If anyone has any ideas on why we’re seeing this water and how it might be emerging from this point, that would be great. We have warranty for another year, so that’s a bonus if we need it,
Many thanks,
Ben