Endpoint /games/getgameinstancesjson does not return results for startindex of 5000

Bug Reports Website Bugs
1

When specifying a starting index greater or equal to 5000, the endpoint will no longer return server data.
Example: Adopt Me! averages over 10k servers. So you should be able to specify a starting index of 5000, Right?

Let’s provide the respective parameters: https://www.roblox.com/games/getgameinstancesjson?placeId=920587237&startIndex=5000

You will notice the Collection property is unpopulated, weird. The total server count (TotalCollectionSize) is 17608, so we should have been able to index up to 17600.

Now let’s try a starting index of just 10 lower: https://www.roblox.com/games/getgameinstancesjson?placeId=920587237&startIndex=4990

Now Collection is populated with server data.

You will find this applies to all games with a server count >= 5000. Sometimes 4500, but I’m not sure why.

2

My current hypothesis is that the rest are taken up by private servers, though I’m also open to the interpretation that Rōblox now obscures less populated serves from the listing.