Long Load, Reloading, and Poor Resolution on C71KW-400

Hi,

We have two of the DIRECTV Stream boxes that we use regularly. (model C71KW-400) We have gigabit internet service. On a MacBook pro wired with Ethernet, we get 950-990 Mbps. On various devices on WiFi, we get anywhere from 250-800 Mbps. (the router is WiFi6) One Box is on WiFi, one is Ethernet wired. On both boxes, we have issues which are getting progressively worse with streaming. On both live TV and DVR playback, we are consistently having the following issues across multiple channels: 1.) Upon tuning to a channel, it will sit there with the screen with the blue bar stretched across the screen for a long time, sometimes more than 30 seconds, before the channel will start. 2.) The program may intermittently freeze, and most of the time this is happening, it will say something like "Your programming is loading. Thank you for your patience." 3.) Usually in conjunction with the other two symptoms, the picture quality is miserable and in Settings - General, it says it is "SD 480p" instead of the "Full HD 1080p" we usually get otherwise. A network diagnostic on the boxes only claims a speed of 11-13 Mbps, but deems it "strong". This is getting to be a nightly problem and we are considering switching services as this is frequently preventing us from being able to watch programming. On top of this, customer service has not been very helpful, having very limited hours and taking us in troubleshooting loops. I have verified our internet is good, the boxes have been restarted, restarted, and restarted again, and one even factory reset twice. The router is regularly restarted as a troubleshooting step as well. Thanks for any help or suggestions.