Keep an eye (or ear) on it. If it is the auxiliary belt, failure is not terminal, but potentially inconvenient. Might need a new tensioner.
New cambelts often sing gently but this should disappear, however, my Doblo, (1.4 Twin cam 95hp), had a new belt fitted, by a 'professional' beginning of January. Belt sang gently, more so than expected, as I've done a few over the years. The noise diminished, but never went away, whereas the Panda 1.2 is silent. Recently, it has started to whine, not immediately on startup, but after a few minutes, then continues. Can sound worrying from outside.
I investigated. Every fastener to gain access was overtightened. Removed auxiliary belts, noise still there. Cover off the cambelt revealed a paint mark on the cam pulley, suggesting locking tools not used, so may also have been tensioned at TDC, instead of with the pistons mid-bore. Belt is very tight, never seen one this tight before. Already looking old, despite being only a few months and 2000 miles. Tensioner is singing loudly, not a happy tensioner, and water pump is also leaking.
Sadly, due to warranty, has to go back to the same idiots for replacement.
These rotational tensioners can be very fiddly to set up. Initially they need overtensioning, rotate the engine by hand two turns, then release and tension correctly. My guess is that is was done at TDC, which may affect the tension as the cams will be in different places, and may be pushing back, and that the initial overtight was left.
Tensioner is also hiding behind the engine mounting, and on the Panda, is very difficult to see. On the 1.2 it is necessary to juggle a mirror and some light, whilst setting the tensioner and tightening the bolt. Very fiddly. Doblo has a little more room, and if still singing when I get it back, I will probably have to do it myself.