Hi, Phil, this is the first I’ve heard about your headache even though we live not too far apart. As you know I’ve similarly complex situation with several blocks, DCS and TMCC, not yet using multiple TIUs but otherwise similar. Your former profession involved diagnostic thinking, like mine. I wonder if you’ve sat down and considered exactly what thing(s) changed, by you or anyone relevant, just before things went to H in a handbasket? The only “environmental” item in my personal layout history was wondering if the multiple fluorescent lights in the basement were contributing stray frequencies. After changing to all LED replacement tubes, there was an improvement in running TMCC I believe; not sure I was using DCS enough back then to comment on a change. I know that belated “what did I change last” thought has saved me a few times :-). Would be glad to discuss by phone. I’ll email you to make sure you have my cell number.