hello, please in my plugin i'm trying to get epg (now/next )from sat , after restart all thing works fine but after few minutes for some channel its began to lost their epg the command

self.epgcache.lookupEvent(['IBDTSERN', (str(ssrvid[0]), 0, -1, -1)])

give me an empty list, please how can resolve this prob ? if its a problem of epgcache so how can i update it without restarting or rebooting enigma? (sorry for my bad english.)
thank you