There is no exact solution to solve this issue. But Apple recommends some steps so, you can give it a shot to solve your issue.
Step 1: Press and hold the power button for 10 seconds, if your Mac is on when you do this, it will turn off.
Step 2: Unplug all the external Accessories from your MacBook Pro including the USB Cable and also remove the card inserted in the SDXC Card slot.
Step 3: After trying the above steps if you still face a problem then, Reset the SMC (System Management Controller) with a non-removable battery.
Step 4: And then, you can Reset NVRAM or PRAM to solve this issue.
Step 5: At last Contact Apple support and ask your queries.
Apple has not yet provided clear details about what’s causing the problem. But they have given those above steps temporarily to solve your problem. Apple’s support article will be published soon. Do get updated. Stay home Stay safe 🙂