Fixed single variable request

PythonServer/pos-python-server.py

@@ -49,11 +49,14 @@ def epics_callback(name, value):
 def get_pvget(pvlist: str):
     global monitored_pvs
     global monitored_epics
+    result_pvs = {}
     pvnames = pvlist.split(",")
     for pv in pvnames:
         if pv not in monitored_epics:
             monitored_epics[pv] = epics_ctxt.monitor(pv, partial(epics_callback, pv))
-    return json.loads(json.dumps(monitored_pvs).replace("NaN", "null"))
+        if pv in monitored_pvs:
+            result_pvs[pv] = monitored_pvs[pv]
+    return json.loads(json.dumps(result_pvs).replace("NaN", "null"))
 
 
 @app.get("/api/v2/cleanpvs")