How is your HDD connected to the PC with storagenode?
Canceled uploads or downloads can be result of cut of long tail or canceled by customers.
Every upload is cut up into 110 erasure encoded pieces of which 29 are needed to recreate the data. Uploads stop after 80 of those pieces have been uploaded successfully. The other 30 nodes who were the slowest for that transfer will see the upload canceled error in their logs.
The same for downloads, but uplink selects 39 nodes for download and stops others when 29 is finished first.
So, your node is slower than competitors.
You can’t improve it with a bandwidth or storage limit. The only viable way to connect your storage directly to the PC and avoid any network connected storage. If you already have it directly connected, then there is nothing you can do. You can’t win all the pieces.