Outside the U.S., we've found that the BirdNET app is usually better than Merlin at recognizing birdsong.  The drawback is that you need an internet connection to submit your recordings.  However, it does tell you its level of confidence in its identification, something I wish Merlin did.  We had good success in both Japan and Malaysia, including recognizing some endemics.  That's the thing with Merlin: it may recognize 40% of birds in a given country, but not endemics or unusual birds.