Hey since posting I've repaired my game
Which seems like an obvious first choice, but I've literally just newly re-installed the game. I had to get my laptop repaired and they put in a new hard drive and wifi card. Prior to this, I had tried to fix my laptop by formatting before (when I also re-installed) the game. Before the format, I had tried repairing the game for this issue to no avail.
So several repairs and re-installs including a new install didn't make me jump to repair the game right now.
Not sure if it was the repair that did something, but upon re-entering the first location, the entrance with the plane was, for the first time ever, not accessible on that trip and the bridge actually appeared!
I didn't go in prepared because my intention was just to screenshot, but I managed to get to and complete the temple and enter the baths all with one machete and one spider repellent. The entrance to I don't know where inside the royal baths was not accessible, but considering how far I had gotten, I don't mind at all
So I have a new question: is the bridge supposed to be a rare occurrence?