Do you get them all from the same place?

No, they came from different places.

Actually, rubber trees are quite forgiving if you follow a few easy guidelines when it comes to their care. They don't like to be watered until the soil is drying down at the BOTTOM of the container; then, they like to be watered THOROUGHLY, so at least 10-15% of the total volume of water applied exits the container. If you can't do this w/o the soil remaining wet for a week, your soil is probably inappropriate and you need to upgrade or take steps that will help you improve how it performs (more on that if required). If you're watering when they are dry an inch deep, you are probably over-watering, and odds favor that as the issue preventing your success with these plants.

My suggestion is to follow this embedded link to more information about tending Ficus in containers
and read it carefully. In the end, your choice of soil will be extremely important to your ability to manage your plant properly and with the least amount of corrective effort and fewest problems.

If you don't find all you need about soil choice, watering habits/technique and fertilizing, you can ask questions there or here & I'll help.

Al

Green, I agree with Al, soil needs to dry between waterings.

How long did you leave your RT in one spot before moving to another AND another area? Ficus dislike change, especially F. Benji's, but most Ficus don't like to be moved here to there and everywhere. It's best letting a Ficus adapt to sun, room temp, etc.

Ficus Elastica do well in med light to full sun. Don't believe clerks at your local nursery when they say RT's thrive in shade..It's a sales pitch.

If you can grow a Majesty Palm, I don't understand why you can't grow a RT..lol..I have the opposite problem.

In the meantime, find a sunny spot. Check soil wkly, either by inserting a stake/probe or your finger, deep in soil. If either come out wet, wait before rewatering. Check soil again a few days later. When the stick comes out dry, it's time for a drink.
Soil can also be tested by lifting. When dry, the pot will be light in weight, and visa versa. But inserting a stick/stake/finger in the soil is a sure bet.

How often did you fertilize? Toni