I'm sorry to tell you this, but as of yet (at least AFAIK), there is no way to downgrade an HTC 8X device. The flashing process, for some reason, runs a version check and halts if the current installed version is higher than the one you're trying to flash.
As of now, the only ROM versions that have been released for the HTC 8X are quite old Asian and European stock roms, which do not really help if you've updated your phone.
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