The two relocated to his native Denver, which involved Lauren quitting her job, and as the source insists, she "changed a lot of what she enjoyed doing to please Ben."
Expanding on this issue, the insider continues, "They both really wanted to make it work, but Lauren was the only one who was really needing to change a lot of things... She felt like she wasn't being authentic to herself."
In the statement announcing their separation, the reality stars—who went on to headline a spinoff titled Ben & Lauren: Happily Ever After?—, said, "We feel fortunate for the time we had together, and will remain friends with much love and respect for one another. We wish nothing but the best for each other, and ask for your support and understanding at this time."
A separate source close to Bushnell previously told E! News it came down to wanting "different things." The insider explained, "They had been struggling for a while...It was a mutual break up for the most part."
"At the end of the day, though, they gave it a good shot," the first source says.
"2017 I hope is the year that we have huge steps in either getting married or having a really good idea of when we're getting married, but right now we don't," he admitted.
—Reporting by Alli Rosenbloom & Beth Sobol