Why is my device ban eliminated after I swap bad motherboards?

So I have two iPhone 8's, my new one and my old one. I got permanently banned from Reddit on my new iPhone and it appeared to be on the device level. I knew this because I made new accounts, changed my IP adress, reset the phone, but the permanent ban stayed on the new iPhone. I also did research and the consensus said when Reddit does perma bans, it's a device ban that cannot be evaded without getting another phone. My old iPhone was never banned so one day I swapped the motherboards of the iPhones so I can use the app on my new iPhone. This means I put the old, not banned motherboard in my new iPhone body, and vice versa. As expected, I was able to use the app on the new phone (old, not banned motherboard). But to my surprise, I could use Reddit on the old iphone (new but previously banned motherboard). I cannot figure out why the previously banned motherboard became unbanned, to my knowledge the device ban meant that the motherboard was perma banned. Does anybody have an explanation for this?