Junebug1951:
This was a very old post from you, but I just noticed it. I had a similar experience, and I do not do match play. I shot a 29 in a 9-hole tournament round, and my WGT average immediately went from 68.30 to 61.68. That is the only round I have shot as a Tour Master which is in the 61 range, and the low average is clearly a mistake. I sent a message to WGT about it, but got no response. My average has worked its way down to 61.30, going lower when I shoot the occasional 65, and I assume I will be at Legend at some point while shooting only one Legend-worthy round.
You are certainly saturated at TM - congrats.
Of course when you shoot any round lower than current average, the highest saved score is replaced with the new lower score, so the change can be noticeable, but not usually that much. Shooting a score above your average will not bring your average down, so something else is going on.
Note that WGT uses pure averages (based on an 18-hole equivalent), so that 29 translated to a 58 for 18 holes. They don't consider par when computing average.
Legend is a big change, but look it as a challenge!!
Good luck.