19 minutes ago, csleaver said:

When I have experienced Vault hub covers falling off multiple times even after being installed correctly using red 271 (or similar) thread lock, it was usually caused by a crack in the rotor hub.  When the rotor hub gets hot the crack will allow it to expand enough for the Vault cover to fall out.  The crack may be so small that it isn't even really visible.  Replacing the rotor hub has been the most consistently effective solution. 

Wow, I really hope my hubs are not cracked! It would suck to have to now replace those too. What temperatures would be needed to do that?

The only other things I saw from your earlier post and photos that may be an issue were:

The hub nut should be torqued to 18-20 inch pounds, or slightly more than finger tight, not to 20 foot pounds.

The cotter pins were not bent over as recommended which may interfere with the Vault cover install.

The zerk fitting should be removed before installing the Vault covers. 

Here is a link to the Vault service instructions, if it helps.

https://www.dropbox.com/scl/fi/vwsx92z1bwu50wukojrvf/The-Vault-Hub-servicing.pdf?rlkey=dsnrgbs9rfbo4cje6zgzcwkmt&dl=0

We've got a Hovercraft. Great fun but still much prefer my Radar Senate Pro build. The Hovercraft is for playing around on and for teaching learners (we've ditched the combos). 

When I have experienced Vault hub covers falling off multiple times even after being installed correctly using red 271 (or similar) thread lock, it was usually caused by a crack in the rotor hub.  When the rotor hub gets hot the crack will allow it to expand enough for the Vault cover to fall out.  The crack may be so small that it isn't even really visible.  Replacing the rotor hub has been the most consistently effective solution. 

From my experience, most intermittent or random electrical issues are caused by loose, worn, or corroded connections.  Most PPS failures I've seen tend to occur as the throttle lever is initially moved from the neutral position to the in-gear idle position or at the wide open throttle position.