Voice Message Storing

I had a voice recording sent to me via iMessage and i hadn’t played it since receiving it. However, about an hour and a half after receiving it, I went to play the message only to find that it wasn’t even there for me to play, and then I couldn’t even find the notice of the message’s existence. I’ve dug around here for a bit and I have now two new questions and no answers. These questions are as follows: a) how does an iMessage voice recording get stored if unplayed? b) How long is an unplayed recording valid for before it randomly expires? and c) How can I disable the expiration setting for voice messages so that they are stored on my device?

I’m asking the last question because I saw a mention of that in a thread, but my attempt to do so was futile. It would be much appreciate if someone told me because this expiration thing is very annoying to put up with and I find it extremely bothersome that by default any voice message can and will disappear unless I press “Keep” and, frankly, I’d much rather use something like Whatsapp or Telegram or Messenger because they all don’t have this seemingly redundant function, permitting me to go back to voice messages whenever I need to re-listen to them instead of casually just seeing no message at all. Really hopeful somebody may answer at least one of my questions

Thank you in advance.