Slow Ethernet, fast WiFi

Same thing happens with our Tmobile home internet that we've had about a year.  Started getting throttled around June 2023 and has only gotten worse.  Throttling usually begins around 9am to 10am and last until about 11pm.  We subscribe to YouTube TV and the streaming is so blury it's bad on the eyes.  Barely 1mbps speed during the throttling.  The really weird thing is the exact same thing is happening with our phones.  They're about to lose us as a customer on their phones and internet if they don't get their act together.