HDR Auto should only be turned on and used when a HLG or PQ signal is set to output from the camera.
When the camera is connected, the Ninja V detects the info frame (if present) and switches to the REC 2100 PQ setting and PQ monitoring mode. The Ninja V will then record the PQ monitor mode into the file metadata and therefore playback the PQ clip in the PQ display mode.
However, if HDR Auto is turned on and a C-log signal is connected, there is no info frame present, and therefore the signal will default to Rec.709. This analysis for the info frame may cause a momentary freeze whilst the Ninja V is looking for the info frame.
The workflow in this case, is to use the Log/HDR functions within the Input menu, to set Atom HDR to Canon setting with C-log Gamma and BT.2020 Gamut.
(note: Rec.709 is not available, as this has not been used with C-Log by Canon)