Hello everybody,
Since a few days some brown stains have appeared on a few leaves of my Ficus Retusa.
I have it since 2013, I keep it inside in winter and on my terrace with all my other trees when temps are above 10-15 C.
It has always been thriving so far and I am now a little worried.
Could it be a fungus? Or maybe some sun-scorched leaves?
Thanks!

White spots are stains from hard tap water.
Dark spots could be natural ageing of the leaf, or a fungal issue.
I would cut the affected leaves and observe the others remaining.

Hm.. It does look a lot like sunburn spots too though..

Thanks a lot Clicio and LB, I'll remove the affected leaves moving the tree to a bit more shaded position… and will look at it hoping for the best!