diff --git a/contracts/WIOTXUnwrapper.sol b/contracts/WIOTXUnwrapper.sol
new file mode 100644
index 0000000..df90f0b
--- /dev/null
+++ b/contracts/WIOTXUnwrapper.sol
@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: MIT
+pragma solidity >= 0.8.0;
+
+interface IWIOTX {
+    function withdraw(uint256) external;
+}
+
+contract WIOTXUnwrapper {
+    address public wiotx;
+
+    constructor(address _wiotx) {
+        wiotx = _wiotx;
+    }
+
+    receive() external payable {
+    }
+
+    function onReceive(address _sender, IWIOTX _token, uint256 _amount, bytes calldata _payload) external {
+        require(address(_token) == wiotx, "WIOTXUnwrapper: invalid token");
+        address recipient = _sender;
+        if (_payload.length == 32) {
+            (recipient) = abi.decode(_payload, (address));
+        }
+        _token.withdraw(_amount);
+        payable(recipient).transfer(_amount);
+    }
+}
diff --git a/witness-service/configs/witness-config-ethereum-payload.yaml b/witness-service/configs/witness-config-ethereum-payload.yaml
index ff46cac..ea6cd96 100644
--- a/witness-service/configs/witness-config-ethereum-payload.yaml
+++ b/witness-service/configs/witness-config-ethereum-payload.yaml
@@ -88,3 +88,6 @@ cashiers:
       # USDa
       - token2: "0xeaa38983d3370e35fb42229f89e816e28035a74b"
         token1: "0xBB76063476A79F73624386795f4CcA855954C891"
+      # W-IOTX
+      - token2: "io15qr5fzpxsnp7garl4m7k355rafzqn8grrm0grz"
+        token1: "0x6fB3e0A217407EFFf7Ca062D46c26E5d60a14d69"
diff --git a/witness-service/relayer/service.go b/witness-service/relayer/service.go
index 27c2c2e..5c0357a 100644
--- a/witness-service/relayer/service.go
+++ b/witness-service/relayer/service.go
@@ -581,7 +581,7 @@ func (s *Service) submitTransfers() error {
 			if err := s.submitTransfer(transfer, validator); err != nil {
 				util.Alert("failed to submit transfer" + err.Error())
 			}
-			time.Sleep(2 * time.Second)
+			time.Sleep(5 * time.Second)
 		}
 	}
 	return nil
diff --git a/witness-service/relayer/transfervalidatoronethereum.go b/witness-service/relayer/transfervalidatoronethereum.go
index efdf9a0..74bd23f 100644
--- a/witness-service/relayer/transfervalidatoronethereum.go
+++ b/witness-service/relayer/transfervalidatoronethereum.go
@@ -11,6 +11,7 @@ import (
 	"crypto/ecdsa"
 	"log"
 	"math/big"
+	"strings"
 	"sync"
 	"time"
 
@@ -382,7 +383,7 @@ func (tv *transferValidatorOnEthereum) Check(transfer *Transfer) (StatusOnChainT
 	switch errors.Cause(err) {
 	case ethereum.NotFound:
 		if transfer.nonce <= nonce {
-			if transfer.updateTime.Add(5 * time.Minute).Before(time.Now()) {
+			if transfer.updateTime.Add(10 * time.Minute).Before(time.Now()) {
 				return StatusOnChainNonceOverwritten, nil
 			}
 			return StatusOnChainNotConfirmed, nil
@@ -397,7 +398,7 @@ func (tv *transferValidatorOnEthereum) Check(transfer *Transfer) (StatusOnChainT
 	default:
 		return StatusOnChainUnknown, err
 	}
-	if transfer.updateTime.After(time.Now().Add(-10 * time.Minute)) {
+	if transfer.updateTime.After(time.Now().Add(-20 * time.Minute)) {
 		return StatusOnChainNotConfirmed, nil
 	}
 	// no matter what the receipt status is, mark the validation as failure
@@ -465,6 +466,9 @@ func (tv *transferValidatorOnEthereum) submit(transfer *Transfer, witnesses []*W
 	case ethereum.NotFound:
 		return common.Hash{}, common.Address{}, 0, nil, errors.Wrap(errNoncritical, err.Error())
 	default:
+		if strings.Contains(err.Error(), "could not replace existing tx") {
+			return common.Hash{}, common.Address{}, 0, nil, errors.Wrap(errNoncritical, err.Error())
+		}
 		return common.Hash{}, common.Address{}, 0, nil, err
 	}
 }