Why did he call me and then ghost me?

Hooked up with this guy over the weekend. Kind of knew it was just gonna be a hookup but the sex was so good and there was definitely some chemistry there. He took me on a date and actually made some effort to get to know me. The day after our date/hookup, he left for a trip. The night before, when he left my place, he texted me and even called me to check on me. When I said goodnight, he didn't respond and it's been 3 days without a word from him. He even unmatched me on Hinge (which is where we met). Just confused as to why he texted me/called me when he left my place and then went ghost.
Why did he call me and then ghost me?
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