I have a MacBook Pro (13-inch, 2017, Two Thunderbolt 3 ports, no Touch Bar). I have found a good solution that works for me every time this happens. The answer is to reset your System Management Controller (SMC). The full article can be found here: https://www.macworld.com/article/2881177/macs/how-to-reset-your-macs-nvram-pram- and-smc.html
Yet another component of your Mac’s hardware that stores crucial settings is the System Management Controller (SMC), a circuit that deals with power management, temperature monitoring and fan control, status lights, keyboard backlights, and a few other components. If your SMC becomes confused, you could experience problems like excessive fan noise, slow performance even though Activity Monitor doesn’t show the CPU being overtaxed, apps that take forever to launch, batteries that don’t charge correctly, problems with sleep or wake, and so on. (You can see a longer list on this Apple support page.) As with zapping the NVRAM, resetting the SMC to factory defaults may resolve these problems.
Apple says you shouldn’t reset the SMC without first trying other troubleshooting tasks, such as force-quitting problematic apps and restarting your Mac. However, Apple doesn’t mention any negative consequences of resetting the SMC, nor any way to determine for sure if the SMC is glitchy without resetting it and noticing that the problem went away. I’ve reset my Macs’ SMCs many times with no apparent ill effects, and on occasion that did in fact turn out to be the solution to a problem.
Before you can reset your SMC, you must shut down your Mac. After that, the procedure varies depending on the type of Mac you have.
- Desktop Macs: Disconnect the power cord (either from the Mac or from the AC outlet). Wait 15 seconds and plug it back in. Then wait another 5 seconds and turn the Mac back on.
- Portable Macs with non-removable batteries: Shut down and unplug your Mac. On the built-in keyboard, press and hold the Shift, Option, and Control keys on the left side and press the power button and hold all of these down for 10 seconds, then release the keys. Connect the power adapter and then turn the Mac on normally.
- Portable Macs with removable batteries: Shut down your Mac. Disconnect the power cord and remove the battery. Press the power button, hold it for 5 seconds, and then let go. Put the battery back in, reconnect the power cord, and turn the Mac on normally.
