I use 5 active [not passive] TIU's in super mode; 4 blocks per TIU. The signal problem (OOR) occurs within the same block. I repeated the test with a 2nd remote....Same results. I conclude that the problem is in a TIU...maybe more than 1.
I now solicit suggestions re: How to test for a 'bad' TIU. Also, does anyone know how a TIU can 'lose'/decrease its ability to interpret a command? (This is why I was seeking an "expert" ....)