diff --git a/proxy/endpoints.py b/proxy/endpoints.py
index 51d2cce..ec2feb7 100644
--- a/proxy/endpoints.py
+++ b/proxy/endpoints.py
@@ -66,7 +66,7 @@ def _format_nodes(self, nodes):
             if not url_ok(http_endpoint):
                 logger.warning(f'{http_endpoint} is not accesible, removing from the list')
                 continue
-            if not is_node_out_of_sync(node['block_ts'], max_ts):
+            if is_node_out_of_sync(node['block_ts'], max_ts):
                 logger.warning(f'{http_endpoint} ts: {node["block_ts"]}, max ts for chain: \
 {max_ts}, allowed timestamp diff: {ALLOWED_TIMESTAMP_DIFF}')
                 continue
@@ -93,7 +93,7 @@ def url_ok(url) -> bool:
 
 
 def is_node_out_of_sync(ts: int, compare_ts: int) -> bool:
-    return abs(compare_ts - ts) < ALLOWED_TIMESTAMP_DIFF
+    return abs(compare_ts - ts) > ALLOWED_TIMESTAMP_DIFF
 
 
 def get_block_ts(http_endpoint: str) -> int:
diff --git a/proxy/helper.py b/proxy/helper.py
index ccc3609..bb21ad3 100644
--- a/proxy/helper.py
+++ b/proxy/helper.py
@@ -82,7 +82,9 @@ def post_request(url, json, cookies=None):
 
 def make_rpc_call(http_endpoint, method, params=None):
     params = params or []
-    return post_request(
+    resp = post_request(
         http_endpoint,
         json={"jsonrpc": "2.0", "method": method, "params": params, "id": 1}
     )
+    if resp.status_code == 200:
+        return resp