...
The Tau63 values also have events. soil.a sometimes changes from ~6.5s to ~10.5s (loosely associated with rain events). soil.b has a couple of spikes from ~8 to ~4.5 (no relation to rain). These are more than isolated events (especially for a).
?P.S. at about 1540 on 1 Jul, I did unplug and plug in the soil.a TP01 Binder. There wasn't anything obvious wrong. I'll try to remember to monitor it over the next few days to see if Vheat settles down.