It’s not new. I remember when the G5 iMac came out they had numerous problems with burned out midplanes. What I recall was that the Mac when sleeping would turn off the fan and it somehow literally burned out some capacitors and it was a replacement that cost almost as much as a new Mac if it happened outside of warranty or Apple Care. I didn’t own the particular machine, but I recall a relative had one that was always running in reduced mode as he didn’t want to have it burn up. I have not myself encountered any problems so far with poor quality control of my own Apple products though.
It’s still there for me and I watched in HDR yesterday. Check your Netflix settings and make sure you didn’t accidentally downgrade to Standard or Standard with Ads.