The solution is as follows:
- (Make a backup)
- Shutdown
- Connect your macbook with power (otherwise this won't work)
- SMC-reset (power management)
- Hold for 15 seconds: cmd + alt + shift + power
- If you have a MacBook with a magsafe adapter thats fully charged you will see the light change from green to orange for less than a second this means the reset has succeeded.
- VRAM reset (also known as PRAM reset if I'am not mistaken)
Power on and immediately pres and hold: cmd + alt + p + r. This wil restart the machine, hold these buttons until the machine has tried to bootup two or three times then let go.
The problem could comeback but just use this 2 minute trick and your good to go.
Please let me know of this worked for you!
My hardware: MacBook Pro 15 inch 2015 (fully spect). Had this problem with: iPad 2017, Iphone 7+, Ipad 4, Iphone 6. All works well after this reset.