Those people may not want a rematch. It is perfectly okay to decline one without a reason why. Probably after that in the random pairing, he or she disconnected aborted because of the rating difference
Returning rematches.

I understand you treated your opponent respectfully and fair. You can't expect the same reciprocation. Be happy he didn't abandon a game.

So I have basically always accepted rematches unless I have to go or I really need to take a break from chess, and even when I decline I will first tell my opponent why. Most of the time my opponent will also do the same for me when I ask for a rematch but some people will decline without telling me why. Although I can sometimes get angry or frustrated about this, it is not what frustrates me the most. Instead it is when I win the first game against someone and they ask for a rematch and I accept. Then they win the second game and I ask for a rematch and they decline without leaving a note why. Not only that but the second opponent I faced we ended up playing each other again not because of the rematch request but because we got paired up randomly. Then he waited until the time he automatically aborts the game. Although this is quite rare, it happened to me two times in a row today and it made me super displeased. I would like to know if anyone else who had this happen to them feel this way and if they had any solutions to this problem.
My tip is to stop being immature.

A few times the pop-up box disappeared before I can accept a rematch challenge; I usually leave the person a message.

i don't understand this. i don't think i have to accept a rematch. sometimes i just don't want to. sometimes i just don't enjoy playing some people. i don't know why. i didn't know i was being rude. where do you go for the list of chess good manners? seriously, i never knew....
Hi Griffin
Unfortunately sometimes people have to go suddenly for non chess reasons
All the Best