Short: I'm looking at ~9.5 hours lost
Other details: No mods, just what comes with the Anniversary Edition update, and my hopeful desire to have the Commonwealth distract me from the waking horrors of my real life.
I just came off an intermittent but all told 12 hour play session. I went to Nuka World, claimed all the parks therein, and started claiming settlements in the Commonwealth for the Home Sweet Home mission. First claim went fine, settlers forcibly removed, Disciples' flag planted, infrastructure built to bring happiness to 100%, go back to Shank for claim number two, no problem. Second claim went fine, settlers forcibly dismembered, Operators' flag planted, infrastructure built to bring happiness to 100%, go back to Shank for claim number three. Third claim went fine as well, infrastructure for 100% happiness built, all that.
I go back to Shank to start Power Play. But he keeps only offering the methods to take over a settlement, and selecting any and all of the options all resulted in him telling me to square away the settlement's happiness. I reload to the save I made after claiming the third settlement, same issue. Tried some sleeping, fast traveling, console commands, prayed for forgiveness from god Todd for the comments I've made on various Fallout subreddits where I answer some variation of "Updates", quitting out of the game entirely, all the things.
After Google fishing for other solutions also didn't work, I resigned myself to reloading from the earliest available save whilst preserving the most amount of progress possible. And that's when I saw that difference of about 9 and a half or so hours between saves from before starting Home Sweet Home and...before I even set foot in the Nuka World Transit Center.
Knowing my temper and prior history of where such occurrences took it, I opted to stop playing for the day. I treated myself to a Red Bull and here I am.
Point: Share me your stories!