I thought I read in several places that the 5-day visa was suspended only for US passport holders because of diplomatic reasons, but of course this could be wrong.

As for your experience, I have a question: the last time I went through the checkpoint and got a 5-day visa was in 2002. That time and the prior time, the visa office was upstairs, such that as you were walking from the border to the immigration checkpoint, you had to do a U-turn and walk up a flight of stairs or take an escalator to the next level and go inside the office up there. If that's the case, how did you notice that the office was closed?