That is odd. I used my vLemmy account and was able to search and find that community with wefwef and the mobile browser.
I haven’t read the entire guide, but if no one from your home instance has searched for a certain community on another instance, it won’t find it until someone searches with the full instance name to initialize the connection. For example, if no one from vLemmy has done this for that Education community, I would need to go to Communities > select All > search “[email protected]” and wait for the spinning wheel. It’s not intuitive, but after a few seconds vLemmy connects with that community and can now be searched. So you delete your search text, keep All selected, but now can just search “education” and it should become visible with the option to subscribe.
Let me know whether that helps or you’re still getting stuck.