Bluetooth headsets Airpods Max cutt out on iMac 5K

Hello everyone,

I am having an issue with the Airpods Max I recently puchased.

They work perfectly on my iPhone, iPad and AppleTV but they keep cutting off on my iMac 5K (2014)

At the beginning they work fine but when I try using my Bluetooth keyboard or mouse at the same time they start cutting off.

I was previously using the Beats Studio 3 and had the exact same issue.

However the problem doesn’t happen with Airpods Pro, only with Bluetooth headsets.

It appears it is definitely a Bluetooth problem as it appears when I use other Bluetooth accessories but only with headsets not with Bluetooth earbuds.

And it doesn’t seem to come from the headsets because they don’t have any problem on other devices.

Does this model of iMac have Bluetooth issues ?

Does anyone have an idea or a way to fix this issue ?

Thanks a lot