Example of a broken/stale sync: https://lemmy.world/u/debby@hear-me.social shows no activity for 6 months, despite her actual Mastodon profile (https://hear-me.social/@debby) having posts as recent as an hour ago.
Alternatively , is there a good way to find decentralized, actively-syncing Mastodon instances/accounts for Lemmy myself?
Lemmy only has limited support for mastodon, so unless they tag a threadiverse community in their post it won’t reach a Lemmy instance. Mbin and since recently also Piefed have better support for mastodon
that explains why we haven’t hear from them in a long time. lol