Solana NFT, fails to upload to candy machine

Hey.

I hae created an NFT project with Hashlips’ art engine. I am now in Hashlips’ Metaplex Master in VSC trying to upload the NFTs to the candy machine. About 1,000 out of 1,111 have successfully been uploaded and indexed on-chain, when I ran this code:

npx ts-node js/packages/cli/src/candy-machine-cli.ts upload ./assets --env mainnet-beta --keypair /Users/XXXXXX/.config/solana/mainnet.json

But the rest haven’t been added to the .cache folder, it just says this for each one:

Error uploading file XXX Error: failed to get recent blockhash: FetchError: request to https://api.mainnet-beta.solana.com/ failed, reason: connect ECONNREFUSED 5.62.126.XXX:XXX
    at Connection.getRecentBlockhash (/Users/XXXXXX/Desktop/metaplex-master/js/node_modules/@solana/web3.js/src/connection.ts:2925:13)
    at runMicrotasks (<anonymous>)

and this

 at processTicksAndRejections (internal/process/task_queues.js:95:5)
    at async Function.fetchIdl (/Users/Oliver/Desktop/metaplex-master/js/packages/cli/node_modules/@project-serum/anchor/src/program/index.ts:311:25)
(node:11804) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 293)

Anyone who knows what to do? When some files first failed, it just automatically ran again until they succeeded, but it seems it has gotten stuck with the last few. The failed files are random ones, not in any particular part of the collection. Thanks. @HashLips