Order size refused above a certain amount in DXtrade

What is causing it

A maximum lot size, maximum position or maximum exposure limit set by the firm, or a size step the instrument does not allow.

Why this happens

Size caps exist so a single trade cannot blow through the firm's own risk allowance, and they are enforced before the order is routed. Because the check happens instantly, a capped order looks identical to a broken one. The give-away is repeatability: a fault would not reliably accept 0.5 and reliably refuse 2.0.

The fix, step by step

1. Halve the size and try again to find roughly where the ceiling sits. A clean ceiling points to a firm rule.
2. Check whether the limit is per order or per instrument in total. Some firms cap total exposure, so several small orders will also be refused once the total is reached.
3. Check the instrument's minimum size and size step in its contract details. A size that is not a valid multiple of the step will be refused whatever your limits are.
4. Check whether your open positions elsewhere are consuming the allowance, and close or reduce them if so.
5. Confirm the limit with your firm for your account size and stage, as the cap usually scales with account size and is often lower during evaluation.
6. If the size box itself refuses your input, you are hitting an interface limit rather than a rejection, which still points at a configured maximum.

How to confirm it is fixed

An order at or below the limit is accepted, and one just above it is refused, consistently. That is a cap working as designed.

Stopping it happening again

Note the cap for your account size and build your position sizing around it, including any total exposure limit across open trades.