After my run this morning, I saved and then quickly scrolled through the pages reviewing the content before diving into "all details" in the sub menu. When I initially scrolled the Training Effect was shown as "Tempo" but when I returned to the main screens after going into the sub-menu it had changed to "Base."
I am certain I saw "tempo" because I was a little disgusted at it because I purposely tried to back-off a bit on effort on this run because I had two hard days preceding it. But high temps/humidity made it a tough run regardless. But now that it's "base" all is okay.
Anyway, I bring this up not because I think it's an issue with the watch, but it gives us some insight into how these metrics are calculated. Apparently sometimes the algorithms need a bit of time to settle/fully-bake!