FWIW not sure if this is applicable to you but if someone behind your public IP address happen to be using a program to download videos from them such as yt-dlp without enabling rate limits in the application then they will eventually start responding to your requests with TCP reset packets. I have a theory that a factor in their decision is the PTR reverse DNS record based on my testing. My work around was to do the automated downloading from random throw-away VM's in the cloud in a GNU screen session with rate limits and delays, then rsync what I want to keep when it finishes. Otherwise it could be just a network glitch.