Here are a few common reasons for Limit Orders not being filled.
The limit order price target might not have been reached
Please note that even if the global market price shown on sites like Coingecko or Coinmarketcap appear to have crossed your limit order's asking price, this does not necessarily mean that your order will automatically get filled. A KyberSwap limit order will only get filled when there is a taker for the limit order at the asking price on KyberSwap or on another decentralized exchange that has integrated KyberSwap Limit Orders as a liquidity source.
The order might not have been profitable for a taker
Takers must consider the order's size, gas fees, and personal profit margin before deciding to fill your order. Furthermore, some takers might only fill part of your limit order, and then seek out more profitable orders elsewhere.
The order involves tokens that have low trading volumes
Orders that involve exotic tokens or token pairs may have fewer takers to fill the order.
The order involves tokens that have non-standard logic
The limit order feature was designed with the most commonly traded standard ERC20 tokens in mind. Some tokens have non-standard logic and features (e.g. fee-on-transfer, treasury lockup) which may interfere with the correct operation of the limit order feature. Please do your own research on unfamiliar coins before trading them.