I have a rubber tree plant that has some brown spots on its leaves. This plant is 10 years old and I cut it back every year, so this is new growth.
Brown Spots on Rubber Tree Plant
Certified GKH Gardening Expert
Do you fertilize it regularly? It may be that the salt from the fertilizer has built up and the plant is getting a bit sick from it. Try repotting it with some fresh soil. While you are doing that, just check for root rot too. This is the less common reason for spotting on this plant.