When I answered yesterday, I didn't look at the actual game, as the reason for the behaviour seemed clear in the Inheritance/Lighthouse interaction. I now looked at the game and what happened, the answer is still the same: No bug.
I went through the log 4 times, looking for mentioning of "Lighthouse", "Mountebank", "Soothsayer" (the 2 attacks in the kingdom) and "Black Market" (a potential source for other attack cards).
1) Whenever "Lighthouse" was mentioned. If you played a "real" one (not the inherited one), I looked what Lord Rat did their next turn. They never attacked, mostly playing their Jack of All Trades.
2) Whenever "Mountebank" was mentioned. If it was played by Lord Rat, I looked at what you did your previous turn. You had played an inherited Estate in some of them, but never a "real" one from your hand.
3) Whenver "Soothsayer" was mentioned. Only you gained one, so Lord Rat never played one.
4) Whenver "Black Market" was mentioned. You had one and bought a Steward and Sir Martin with it. Sir Martin never was played, neither by you nor Laord Rat.
So I'm still standing by my previous analysis. You unfortunately never had a Lighthouse in play when Lord Rat attacked you, so you were not proteced.