When my Mod was installed, the contractor programmed it, showing me how the 'copy' feature worked.
On a few occasions, I tweaked the program, but I could not get the copy feature to work (in 7 day mode). I did discover that it would work in 5/2 mode (a minor inconvenience).
Some months later, after complaining about a room temperature droop, the contractor and a Rheem specialist, came out and checked out my furnace and stat. They wound up replacing a 411 with a 411.
I could not get the stat to copy (7 day) so I just programmed each day individually, thinking that I was doing it improperly.
After re-reading the manual several times, and still being unable to copy properly, I just changed to 5/2 day mode and everything works just fine.
Since my droop (main problem) was corrected, I decided to leave well enough alone and just use the stat as is.
It seems unusual that the first stat would lose the 7 day copy feature, but retain the 5 day copy, and the second one would not be able to do it at all.
Just wondered how many of you PROs have (or haven't) come across this problem.