Init Token Account error - "Error processing Instruction 0: custom program error: 0x0"

In my program I'm trying to init PDA Token Accounts so that my program can store tokens of specified mints like this:

#[derive(Accounts)]
pub struct StartAuction<'info> {
    #[account(init, seeds=[&state.positions_count.to_ne_bytes()], bump, payer = authority, space = 5000)]
    pub position: Account<'info, Position>,

    #[account(mut, seeds=[b"state"], bump)]
    pub state: Account<'info, State>,

    pub token: Account<'info, Mint>,
    pub token2: Account<'info, Mint>,

    #[account(init, payer = authority, token::mint = token, token::authority = position)]
    pub vault: Account<'info, TokenAccount>,

    // #[account(init, payer = authority, token::mint = token2, token::authority = position)]
    // pub token2_vault: Account<'info, TokenAccount>,

    #[account(mut)]
    pub authority: Signer<'info>,

    pub token_program: Program<'info, Token>,
    pub rent: Sysvar<'info, Rent>,
    pub system_program: Program<'info, System>
}

If the token2_vault account is commented like shown above everything is good. But when I uncomment it (to have two Token Accounts for different mints), I'm getting a confusing error: Transaction simulation failed: Error processing Instruction 0: custom program error: 0x0.

Assuming that this is the NotRentExempt ("Lamport balance below rent-exempt threshold") SPL Error as specified here and given that the authority account definitely has enough lamports, it's completely unclear why I can init one account but not two, with such strange error.

Thanks in advance!

I solved it by adding seeds to the accounts definitions, like this:

#[derive(Accounts)]
pub struct StartAuction<'info> {
    #[account(init, seeds=[b"vault1".as_ref()], payer = authority, token::mint = token, token::authority = position)]
    pub vault: Account<'info, TokenAccount>,

    #[account(init, seeds=[b"vault2".as_ref()], payer = authority, token::mint = token2, token::authority = position)]
    pub token2_vault: Account<'info, TokenAccount>
}

I guess without defining seeds those two accounts had the same address which caused the error. Why this generates the 0x0 NotRentExempt error is still not clear.