Matthew B. Brown argues in article on FAIR Website that Brigham Young did teach Adam-God but was not dogmatic about it as he himself struggled with many aspects of it.
Matthew B. Brown, "Brigham Young’s Teachings on Adam," FAIR Latter-day Saints, accessed February 8, 2022
Summary and Conclusion
Brigham Young was the legitimate successor of the Prophet Joseph Smith but he was not a perfect or infallible man. President Young learned some things about Adam from the written and unwritten teachings of Joseph Smith and he (and apparently Heber C. Kimball) used this knowledge to form assumptions about Adam and also about those Saints who achieve exaltation. This mixture of ideology became an unofficial ‘One Eternal Round’ view of existence. President Young made errors in formulating his ideology because he was evidently not aware of how the Adam-related material restored through the Prophet Joseph Smith functioned in an ancient world setting. Some of Brigham Young’s assumptions about Adam are not compatible with canonized scripture and so those particular teachings are not binding upon any Latter-day Saint.
In conclusion it is only fitting to allow President Brigham Young to have the last word. He has placed the burden squarely upon the shoulders of the Saints when it comes to accepting only those teachings which are cemented in veracity. He said, “How can you know whether [the members of the First Presidency] lead you correctly or not? Can you know by any other power than that of the Holy Ghost? I have uniformly exhorted the people to obtain this living witness, each for themselves, then no man on earth can lead them astray.” “I say to you, live so that you will know for yourselves whether I tell the truth or not. That is the way we want all Saints to live. Will you do it? Yes, I hope you will—every one of you.”