Incomplete webinar recording

Welcome to the Zoom Community, @AinslieM.

Highly unlikely. If you have a Business Account or higher, please ask your internal Zoom Admin to immediately contact Zoom Support by phone to determine if there has been a processing glitch that can be circumvented/reprocessed. 

My experience tells me that someone likely paused the recording early in your event, and realized later that recording should have been on. The Zoom recording processing software wouldn’t “skip” any recording footage arbitrarily. Still, worth the effort to check in with Support.