This is very weird my boomers faction reputation went from idolized and in a couple of in-game days it goes to liked.

Note I don't recall doing anything that hurts this faction reputation is this normal?

Going from Idolized to Like should not be possible. Must be a bug.

Did you just accidentally load an earlier save?

You could have done something to piss them off without knowing it. That would take your reputation down but not ruin it completely.

Reputation does not decrease, only increase in fame or infamy. This has to be a bug.

can you go back there and do rep missions still with them? try the kids perhaps. If it is a bug, that might fix it. Not sure you need the rep if you have their help for the dam already.

Did you put on any faction armour and then gain boomer rep? If you wear faction armour it resets all rep to neutral while you have it on. If you take it off you'll be back to idolized.