"are often disputed" is a correct and usable phrase in written English.
You can use it to describe something that is uncertain or subject to debate. For example, "The origin of the legend of Robin Hood are often disputed."
Given the political schisms between many of the countries that are represented, however, the decisions of the judges are often disputed.
Although numerous ranking systems or league tables for higher education have been established, but they are often disputed and argued on their credibility and functionality.
As a first, low-cost pass at empirical evaluation, we conduct an experiment among farmers in the Ethiopian highlands, a region exhibiting features typical of countries where borders are often disputed.
The strength of China's economy is often disputed.
The accuracy of claims about the impact of boyband breakups is often disputed.
It is an iron law of literary estates that their ownership is often disputed.
The mystical nature of the sefirot and the precise way in which they function were often disputed.
The so-called Huxtable effect is often disputed, but Cosby told the New York Times in 2008 that his show definitely had an enduring effect on racial views in the US.
In a just world, the answer might always be "you"; in this world, it's often disputed, and the outcome — the rules, and the winner — depends on who's looking at you, and on what words, images, allies, and (not least) funds you have on your side.
While keeping alive a dream of home, they stay in places they have constructed themselves with their bare hands, on unsafe ground, dangerous hillsides, marshy swamps and arid expanses of land the ownership of which is often disputed, and from which they are liable to be evicted at any time without warning.
As in many environmental fields of study, the evidence is often disputed.
