nostr:npub1s6z7hmmx2vud66f3utxd70qem8cwtggx0jgc7gh8pqwz2k8cltuqrdwk4c nostr:npub1g8al4jxjc8cc8rsaqeydhpds483enk5yhpsf42sd2qy8m2fltluspp5svt well 15 minutes later it does show up. So maybe it just needs to wait for a cron job? Likes are instant.
This is what should have been sent to your instance. Now if I like my alter ego nostr:npub1m930ns0wrmzl9w5hxw003aejey5086hlk3jenw6uxheg9jplvv2qmz4fr3 it should show up on mastodon . nl too. 
Discussion
Turns out Mastodon doesn't like it when it asks about a user and the server doesn't reply for a minute and then hangs up with HTTP 499 :-) cc nostr:npub1q3sle0kvfsehgsuexttt3ugjd8xdklxfwwkh559wxckmzddywnws6cd26p