In-game I got the two advancements Those Were the Days and War Pigs, although in the discord channel the bot reported that I got "Find Bastion" and "Loot Bastion" respectively. It seems that none of the other advancement titles match up either.

DiscordSRV uses the advancement's internal name. "Those Were The Days" is obtained from finding a Bastion, and War Pigs is obtained from looting a Bastion. That's what they're called internally so we use it, though I don't remember exactly why we don't use the in-game names for advancements but I believe it had something to do with i18n. pretty sure it's because they're achievements in older versions, advancements in newer versions, and we want to support as many versions as possible

I don't remember exactly why we don't use the in-game names for advancements but I believe it had something to do with i18n.

iirc advancement names are handled clientside for localization, so the server never knows what the "pretty" name is.

I don't remember exactly why we don't use the in-game names for advancements but I believe it had something to do with i18n.

iirc advancement names are handled clientside for localization, so the server never knows what the "pretty" name is.

Ah, that's it.

Makes sense. Thanks all!