Bluetooth mouse dropout on High Sierra

guype wrote:

Apple mouse drops out every few seconds, then need to click several times to reconnect, or manually go through the Bluetooth menu. Frustration doesn't adequately describe the effect that this has. Several closed threads describe the same thing happening to other people; none of the suggested solutions worked. What seems to have worked for me is to delete the device from Bluetooth preferences and then rediscover and connect it as though it is a new mouse. I tried other things first, so it may have been a combination of those things and deleting the mouse from the Bluetooth prefs that did the job.

You can try resetting from shift option keys click the BT icon in the upper right menu bar>Debug

Bluetooth: Unreliable wireless performance may occur when USB 3.0 external devices are close - Apple Support

Potential sources of Wi-Fi and Bluetooth interference - Apple Support