iTunes auto-selects "Download HD When Available", even when I uncheck it

Thanks for the attempt, but my issue isn't in preferences. Like I said, it's in the store itself that the setting is located. Regardless of the preference I choose in the settings, the "Download HD When Available" setting in the store purchase screen always defaults to being checked off. Whether I uncheck the checkbox, then switching to library, then back to the purchases screen...or unchecking it, closing the app and reopening it, then going back...the box becomes checked again and the setting is reset to default.

I did try your suggestions a just in case, but none of them worked for what I'm trying to accomplish. My theory is that the "store" screen is running in a browser-esc sandbox that resets its cookies when its closed, which has a side effect of making this one setting reset to default when the store window is switched back to library. Why they would link that one specific setting to the purchases screen or have it be cookie based in something that cant store cookies is beyond me but that explanation makes the most sense in my head.

Setting in question pictured below just to clarify any miscommunication. (Its blank because I have all my movies downloaded as of writing this.)

Actually, this may be intentional? Since this archived Official Apple Support page (linked below) says the method of redownloading stuff should be through the purchases screen and not the library screen. If I put my mind into "Apple Logic" mode it makes sense in this context since you'll be seeing this screen upon redownloading a movie anyways and in the time inbetween any normal person may have upgraded their devices to ones that at least support HD video.

https://web.archive.org/web/20200330053033/https://support.apple.com/en-us/HT201272#tvshows