Katie and Blake claimed in their statement they had decided to go their separate ways "with mutual love and respect" because they are "not compatible as life partners."
And according to a source, Katie and Blake did not call it quits for any "bad reason," Us Weekly reported.
"They just couldn't make the long-distance [relationship] work," the source explained, adding, "[Katie] didn't want to put on a facade if they truly weren't on the best terms."
Katie just moved into a new San Diego, CA, apartment in August, and Blake -- a wildlife manager who lives in Toronto, Canada -- often travels to Africa for his endangered-animal conservation efforts, most recently involving the rescuing of rhinos.
"Katie really missed Blake once he left and they would get into little arguments, but at the end of the day, Katie wished he would be with her more," the source told Us.
The source insisted Katie, a self-proclaimed cat and animal lover, is "super supportive" of Blake's work and it's "one of the reasons why [Katie] fell in love with him" during their time together on The Bachelorette.
However, the distance between them was reportedly "too difficult for her to deal with."
"They definitely tried," the source shared, confirming that Katie and Blake's split happened recently.
When the pair released their joint breakup statement on social media, they called themselves "grateful" for the moments they had shared together and their entire journey that unfolded this past year.
Katie had added she was most looking forward to a time when she and Blake could stop "traveling back and forth" and stated she'd like to settle down with Blake "eventually."
The couple's breakup may have shocked many fans because less than two weeks ago, Katie had taken to Twitter and clapped back at speculation she and Blake had broken up.
On October 15, Katie tweeted a screenshot of one of her recent Instagram comments that read, "You and Blake are not liking each other's posts. Is all OK?"
The screenshot showed that Katie immediately responded to the fan, "Yes," with a tears-of-joy emoji.
Katie tweeted alongside the image, "Imagine your fiance has been on his [Instagram] stories for weeks in Kenya working his ass off and yet this is what some people notice," in addition to another tears-of-joy emoji.
One of Katie's followers wrote, "But 'liking' posts = love I thought," to which Katie replied in a snarky manner, "I guess that's love in 2021."
"It's hard to say the impact of that in the real world, [if he didn't propose], because you go through so much and you want to take this very seriously -- and a proposal and engagement is very serious," Katie explained at the time.
"I didn't come here to find a boyfriend. I can do that on a dating app," she added. "So it's hard to say if we would have survived just as a dating couple."
"I don't think people fully understand what it's like to date someone from another country and the rules behind that and the visas behind that," Katie said in a series of late-August videos posted to her Instagram Stories.
"I think right now Blake can only be here for 60 days before having to go back to Canada," Katie continued, seemingly referring to how a Tourist Visa works.
"So we really do have a lot we have to look into -- and we just haven't yet -- before we can plan really anything else."
Once Blake left for Africa to focus on his passion for saving animals, Katie reportedly wrote on Instagram earlier this month, "It can feel lonely moving to a new state... I've had trouble sleeping lately... I'm still trying to navigate this new life and city while seeking normalcy."
Katie and Blake had said they were in no rush to wed and intended to travel together and learn more about each other's backgrounds, interests, hobbies and hometowns before deciding on an "anchor spot," or city in which to put down roots as a couple.