As we previously reported, the 25-1 fighter was spotted with several gorgeous women in Florida following his massive win over Devin Haney on Saturday ... one of them being Boor, a social media superstar with millions of followers.

We spoke with Boor after Ryan flew to Miami to be with her ... and she's glad he made the trip -- 'cause they had a ton of fun.

"This was our first time seeing each other in person and we just hit it off," Boor said. "It was just like an instant click."

In fact, Garcia was so into it ... Boor claimed he asked her out right on the spot -- but she politely declined due to his roster of ladies at the moment.

"I said, 'I can't do that,'" Boor added. "Because he has, like, all these girls and stuff and I'm not about it. So, maybe if he changed, maybe the answer would change. But, I don't know what's going on and that's his business."

Don't get it twisted -- Boor spoke incredibly highly of Garcia ... saying he was "so sweet" and made time for all his fans during their beach date, despite being fresh off the biggest win of his career.

"He was just chill," she added. "He didn't act like he was all that. I could not believe how much of a different person he is -- even now posting right now what he's been posting. Compared to what I saw, he's not the same person."

Speaking of that, Garcia raised some eyebrows when he claimed to have bought a $1.5 million engagement ring for a completely different woman after his time with Boor ... but he later clarified that was all fake and he was just caught up in the moment.

We also asked Boor if her following and OnlyFans subscribers have increased since being spotted with Garcia ... and while she admitted she's seen a bit of a spike, she made it clear that wasn't her intention -- she just wanted to get to know the guy.