Thanks Malin for the feedback.
Hi Chris. I don’t know the specific solution for that problem. I can only advice to review the whole procedure, check that the soldering makes proper contact and check the polarity. If you have them, check the old batteries to find out if it’s something with the new ones.
To give you and update, after 1.5 years I can say that mine works perfectly with the Eneloop I bought. Good luck!