@schratze what do you mean? Unlisted toots aren't shown on the web, but you should be able to search for a post by url just fine (as long as that account has permission to view it ofc)
like https://gts-dev.pixie.town/@f0x/statuses/01GPPFXJBFEAGJFY7X4HQXZD94 searches fine here on multiple instances