test: try fix for test_exchangews_ohlcv random failures

tests/exchange/test_exchange_ws.py

@@ -138,7 +138,6 @@ async def test_exchangews_ohlcv(mocker, time_machine, caplog):
         }
 
         # Cleanup happened.
-        # Triggers 2nd call to un_watch_ohlcv_for_symbols which raises ValueError
         exchange_ws.schedule_ohlcv("ETH/BTC", "1m", CandleType.SPOT)
 
         # Verify final state
@@ -149,10 +148,16 @@ async def test_exchangews_ohlcv(mocker, time_machine, caplog):
             ("ETH/BTC", "1m", CandleType.SPOT),
         }
 
+        # Triggers 2nd call to un_watch_ohlcv_for_symbols which raises ValueError
+        exchange_ws._klines_watching.discard(("ETH/BTC", "1m", CandleType.SPOT))
+        await wait_for_condition(
+            lambda: log_has_re("Exception in _unwatch_ohlcv", caplog), timeout_=2.0
+        )
+        assert log_has_re("Exception in _unwatch_ohlcv", caplog)
+
     finally:
         # Cleanup
         exchange_ws.cleanup()
-    assert log_has_re("Exception in _unwatch_ohlcv", caplog)
 
 
 async def test_exchangews_get_ohlcv(mocker, caplog):