Take a look at thist thread I have created:
I have the same type of problem. Today finally I heard back from Yarbo. They told me to try again to connect using bluetooth and make screenshots.
I thought they already have identified the problem as on my greatest thread someone had the same problem and Yarbo fixed it over the air. But I guess not.
Try to do all the things I have mentioned there. Also try to add new Yarbonunit while you are standing near your unit. It then should show you that have your unit completely lost the ability to connect over bluetooth or not. I think that’s why Yarbo made me test this last thing.
My core is still “dead”.