Mastodon Cross-Posting Not Working

How long was it? I just got one of these, when I expected a truncated post to land on Mastodon:

Feed: Error posting to Mastodon, trying again... {"error":"Validation failed: Text character limit of 500 exceeded"}

:thinking:

Manual cross-posting truncated it and added the link, using:

Screenshot 2025-01-26 at 12.37.04 PM