Solana NFT Minting fails with Phantom Wallet: 'Failed to simulate the results of this request

[Azzurriii]

I'm trying to mint an NFT using Candy Machine UI v3 on the Solana network, but I'm encountering errors when attempting to confirm the transaction in Phantom Wallet. Here are the details:

Environment:

Network: Solana devnet
Wallet: Phantom
UI: Candy Machine UI v3
RPC: Helius Devnet RPC
Error messages:

"Failed to simulate the results of this request. Confirming is unsafe and may lead to losses."
"There was a problem estimating the fee for this transaction. It may fail."
"Couldn't fetch network fee"
My .env configuration:

REACT_APP_CANDY_MACHINE_ID=<my id>
REACT_APP_SOLANA_NETWORK=devnet
REACT_APP_SOLANA_RPC_HOST=https://devnet.helius-rpc.com/?api-key=<my key>
SKIP_PREFLIGHT_CHECK=true

I've tried the following:

Ensuring I have sufficient SOL in my wallet (devnet mode)
Checking the Candy Machine configuration
Verifying the RPC endpoint is working
What could be causing these errors, and how can I resolve them to successfully mint my NFT?

Any insights or troubleshooting steps would be greatly appreciated.

Here is the picture of my Wallet when i click Mint button: