This is a services issue specific to the network that you're on.
Did you register the channel using chanserv or the channel registration service on that network?
If not, then that service isn't recognizing that you created the channel, as there's been no information stored in it's database to tell it that you should be auto-opped as the founder.
If you did, then I suggest you see if there's an IRCop or Admin help channel, and enquire there. Worst case, join the basic help channel (usually #help) and mention your problem there.