The Muck Boys Bridge keepers are often invisible to me as a player.

[Egon the Monkey]

The toll keeper NPCs are bugged for me maybe 1/3 of the time. The name shows up, but there is no model to click on. A relog does not fix it, although sometimes it makes their names appear red. Running through the canal is not always a good option to avoid an OC issue.  Could these NPCs be changed to use a "coin box" placeable that activates the transition? It's incredibly rare for placeables to vanish for me, but frustratingly common for the Muck Boys to have disappeared.

[Bacon_Cheese_Burger]

I have had this happen to me also.

[Wavy]

I get this on occasion (along with pcs, etc but that's besides the point). While annoying, exit NWN fully and relog. Should fix it for the time being.