To your first question, yes, it persists--they were never accessible. Only used my own account on the same console. I started a new campaign this morning to test it and the save issue again, and checked on my son's console from his account to see what was going on at his end / with his game. Maybe we're just doing something wrong, in which case I'll feel silly but pleased, but it feels like we've spent a lot of time trying every button or combination of buttons in every different screen trying to access the hud elements. The most natural/likely path to me so far seems to be to use the TouchPad from the map, which opens the encyclopedia. From there, we can glide down to the other hud elements in the bottom left. We see notifications over some of them, but haven't found a way to interact with them. Only one that can be used is the encyclopedia.
RE the save file: After starting a new campaign, I did "Save as", and I could see my old save files from the first campaign in the list. Saved as a new file, quit to main menu, "continue campaign" was now lit up so I clicked that and loaded the new campaign I'd just saved. Was able to load the old campaign from the pause menu. I saved and exited again, and now "continue campaign" works and does load that original campaign I'd put a few hours into. Not sure what went wrong with that first campaign file for the game to "not see it" from the main menu, but it works now. No problem on my son's console. He didn't manually save, but "continue campaign" was usable and loaded his last autosave no problem.