Transactions fail consistently with default RPC

[jthiller]

When delegating DC to an IoT OUI, the command fails consistently :

foo@bar:~$ helium-wallet dc delegate iot <payer> <dc> --commit
Wallet Password: [hidden]
Error: unable to confirm transaction. This can happen in situations such as transaction expiration and insufficient fee-payer funds

Caused by:
    unable to confirm transaction. This can happen in situations such as transaction expiration and insufficient fee-payer funds

However, when declaring an alternate RPC url, the command succeeds on first try.

foo@bar:~$ helium-wallet --url https://api.mainnet-beta.solana.com dc delegate iot <payer> <dc> --commit
Wallet Password: [hidden]
{
  "result": "ok",
  "txid": "..."
}

My hypothesis would be that priority fees or RPC congestion are the issue, but the quick successes I've seen with the Solana Foundation public RPC feels like it would rule out both.

[madninja]

Hmmm the default URL is the foundation one. What’s different about it?