Thank you for your reply, and the added info on your Mac.
Seems your Mac would still be under Apple Care / warranty / too,
and having it checked out by Apple would likely be the best step to take.
How to: Find your Mac model name and serial number - Apple Support
You can enter the serial number on this webpage:
Check Your Service and Support Coverage - Apple Support
or
"One stop for technical support, Apple hardware service, and software support.
Call Apple Support at 1-800-APLCARE (or use the app)
AppleCare Products - Apple
or
you may be able to take the Mac into a nearby Apple store, where they could observe / examine it closely, and give advice. Apple Store - Find a Store - Apple
If you decide to visit an Apple Store:
a Genius Bar reservation is recommended:
Genius Bar Reservation and Apple Support Options - Apple"