for me, leaderboards have started only showing the top x times in each category, where x is a number that seems to be varying arbitrarily - for example, SM64 shows 16 runs for 120 star and 20 runs for 70 star. If I tick "include emulator", the number of runs shown decreases. what's going on?

I'm unable to replicate this issue on my end. There were site load issues that were fixed this morning.

Is this issue still occurring for you now?

nope, seems to be fixed