can't attach usb devices to Virtualbox vm

I use Virtualbox 6.0.14 on Mac osx Mojave 10.14.6 to run a ubuntu 18.04.3 LTS vm.

Since a few weeks, I am not able to attach the built in bluetooth to the vm while I was able to do it for months. When I attach it (Device->USB->Broadcom Corp. Bluetooth USB Controller), I have the following error :

Could not find a USB device with uuid {8b481d93-b91c-4722-ae0a-cba31017edb6} Callee RC NS_ERROR_FAILURE (0x80004005)

I tried with the same vm and same Virtualbox version on a Mac (El Capitan 10.11.6), I can attach the built in bluetooth. I also tried with different versions of Virtualbox on my Mac, does not work. It really seems it comes from very recent automatic apple updates (2 to 3 months).

Would someone help me one this ?