Brown leaf edges in rubber plant

Hello!

We've had our rubber plant for about a year now and it has always been very healthy. In the past few weeks, brown areas have started to appear in some of the leaves' edges (see attached images).

We've checked for causes on the web but we are unsure of what could be causing this. Does anybody know what it could be and how it could be treated?

Thanks in advance!

 

Looks a bit to me like scorch, maybe the leaf was wet and in full sun at sometime.

It looks like a leaf low down on the plant.
These drop off naturally and can become a bit tatty before they do so.

 

Hi Pete! Thanks for your reply.

The plant is indoors and we only water its base, so I am not sure it could be scorch. It is also happening to four other leaves, although the one in the picture is the more damaged.

What could it be?

 

Bacterial leaf spot? Though it does look more like scorch, hmm. Sounds a bit out there, but any chance it could be a mineral problem? Boron deficiency?