Dear Matthew, thanks for your swift reply. Meantime it is working again!
What happened is that I brought it in after being outside for 2 days. It apparently stopped working at noon, while the lithium batteries were new, and still were fully loaded 1.5V each. Btw I love the fantastic battery management of the Audiomoth. Now, I brought it inside and it was getting very hot when connecting to the computer via USB. I let it in a warm room overnight and now all seems to be working again. It might have been the humidity? It was storming and raining though I packed it well in a plastic bag... don't know, will let you know if it is happening again of course, but for now all is fine again! Uf sorry for the little panic! and thanks again for your concern. I love my Audiomoths!
G~