Hey there @Paul_M,
At first glance it looks like the way you’ve implemented the HW watchdog might create some undesired issues that are contributing the video you posted.
The lowest hanging fruit is that I would recommend applying the watchdog on the EN pin, which is designed for resetting the device in an application like this one.
I’ve asked for @rickkas7, who owns our technical documentation, to write up an official application note (HW design + firmware) for implementing a HW watchdog as it is a fairly common need among our customers.
Additionally, I’ve asked for someone on our Sales Engineering team to post here with some best practices around implementing HW watchdogs in the interim while we work on that application note.