Russ put that address on his motions from July-August 2019, and he was denied in October 2019. That means that was his official address on record with the court, and I don't see any returned mail between then and Jan 2021. "Copies have been distributed" was marked on documents entered Oct 2019, Dec 2019, Nov-Dec 2020, and finally Jan 4, 2021. But only that last document was marked as returned. This suggests Russ was officially using that box through Dec 2020, and it probably wasn't renewed into the new year.
Yet the address on the initial Complaint Russ filed in
this suit, on Sept 24, 2020, was different. (It's actually a Post Office, so he got it right.)
Russell Greer
7901 South 3200 West
P.O. Box 152
West Jordan, Utah 84088
801-895-3501
russmark@gmail.com
Pro Se Litigant
The two cities are about 20 minutes apart. Maybe some Greer experts remember what his living situation was at the time, when or if he moved?
Either Russ paid for and checked two mailboxes at the same time, or he let one lapse and failed to update the court while an appeal was pending.
Interestingly, Russ also filed a change of address in
this suit on Jan 4, 2021. That would have been
from the West Jordan address, not to it. This suggests, but doesn't prove, that he had that box for some time while the
Charleston case was in appeals, before switching to a third address. (I don't know what he changed it to, I don't have a PACER account.)

This indicates Russ clearly
knows he needs to file a change of address whenever he switches boxes. But he didn't do it in the previous case, so on Jan 4, 2021 he was briefly known at 3 addresses across 2 court districts.