A lot of resend requests or a high resend ratio in OctoPrint can be quite a problem when trying to reliably print.
For Creality Ender3s - apart from the usual suspects - this can apparently also be caused by the LCD cable, as user @flrnwgnr reported. To quote:
[...]
The day before i printed a drawer and pushed the cable for the LCD just behind it - like this:
And that was the problem! After i re-arranged the cable according to the picture below (as I had it before and as you can see on the picture)
ALL the errors went away - the amount of resend requests went from 16% down to 0% and print artefacts went away.
[...]
Also the problem came back when i pushed the cable back behind the drawer, so in my case this was definitely the root cause of the problem.
So if you are facing these problems: check your printer cable!