diff --git a/src/ucx/communicator.hpp b/src/ucx/communicator.hpp
index 9321bc00..d74550f4 100644
--- a/src/ucx/communicator.hpp
+++ b/src/ucx/communicator.hpp
@@ -99,7 +99,16 @@ class communicator_impl : public communicator_base<communicator_impl>
         }
         else
         {
-            while (ucp_worker_progress(m_recv_worker->get())) {}
+            for (unsigned int i=0; i<10; ++i)
+            {
+                if (m_mutex.try_lock())
+                {
+                    auto p = ucp_worker_progress(m_recv_worker->get());
+                    m_mutex.unlock();
+                    if (!p) break;
+                }
+            }
+            //while (ucp_worker_progress(m_recv_worker->get())) {}
         }
         // work through ready recv callbacks, which were pushed to the queue by other threads
         // (including this thread)
diff --git a/src/ucx/context.hpp b/src/ucx/context.hpp
index 30197370..0dfa3542 100644
--- a/src/ucx/context.hpp
+++ b/src/ucx/context.hpp
@@ -195,7 +195,7 @@ class context_impl : public context_base
         if (m_thread_safe) m_mutex.lock();
         ucp_request_cancel(m_worker->get(), s->m_ucx_ptr);
         while (ucp_worker_progress(m_worker->get())) {}
-        if (m_thread_safe) m_mutex.unlock();
+
         // check whether the cancelled callback was enqueued by consuming all queued cancelled
         // callbacks and putting them in a temporary vector
         bool                                                           found = false;
@@ -212,6 +212,8 @@ class context_impl : public context_base
         for (auto x : m_cancel_recv_req_vec)
             while (!m_cancel_recv_req_queue.push(x)) {}
 
+        if (m_thread_safe) m_mutex.unlock();
+
         // delete callback here if it was actually cancelled
         if (found)
         {