He waited 4 years and is now he’s giving radio silence?

okay so this is my first time doing one of these. But i grew up with this kid from kindergarten to grade 7. I moved schools in grade 8. him and his mom came into my work every other weekends or so. one time he came in and asked for my Snapchat. I gave it to him to catch up with him. we talked for a little while and then eventually we just stopped talking. after a few months of just having eachother on Snapchat without texting or snapping I had unadded him.

That was in 2021. Now present time (about October ish time) I work at the same place and his mom got a job and works with me. I talk to his mom all the time since we are always on shift together and I see her as my work mom. I looked on Snapchat and saw that he still had me added after 4years. I added him back and we have talked a few times, sending snaps back and forth, talking about elementary school. And on Friday we had been sending snaps back relatively fast, not even 10mins would pass before he would answer my last snap. after that we had a 4-5hour long conversation just talking about life and anime (thats how the conversation started. I sent a snap and my Promised neverland manga was out. so he commented on it and we started talking) since we were on the topic of anime and mangas I sent him a photo of a death note fannart I have up on my wall. he started joking about it and said “imagine those yellow eyes staring at you during the night” and I laughed along with it and told him back that it would be creepy and i asked if “he was trying to keep me awake to keep talking. because it was working”. I ended up flirting a bit with him and he had gone along with it at the time but now it’s radio silence.

Since Friday he sent me one snap on Saturday and since then he has left my snaps on delivered. not even opening them. it’s been a few days now and I don’t know what happened.