Why is my Lemmy instance not finding other instances' communities? - Lemmy.world

I made myself a lemmy: https://tortoisewrath.com [https://tortoisewrath.com] You may notice I am not writing to you from said lemmy… because https://tortoisewrath.com/c/[email protected] [https://tortoisewrath.com/c/[email protected]] is a 404. In fact, though it appears to have federated itself with a bunch of other servers [https://tortoisewrath.com/instances], it only appears to be able to see two communities [https://tortoisewrath.com/communities/listing_type/All/page/1]. These were among the first few communities I tried to access ([email protected] [[email protected]] didn’t work but those two did) - since adding those two, I haven’t been able to see any others, even on lemmy.ml [http://lemmy.ml] where the first two were. Is this normal? Do I just need to be more patient and it’ll figure it out on its own, or is there some switch I need to flip to make it do the thing? (Apologies if this is obvious to those who understand the fediverse but I have no idea what I’m doing)