I use pkcon update and get a note that all is up-to-date.Then I go to the Discover gui and load up 170 updates. This is not the first time so they did not just arrive. If this is not a problem that I should deal with...great. I had heard before that the terminal is safer to update with than a gui. Is that a concern I should have?
Thanks for any guidance.

I am guessing that pkcon refresh is the equivalent of apt update and pkcon update pairs with apt (full)-upgrade. Thus Discover may use pkcon refresh to advise there are updates to be installed hence the apparent discrepancy.

I 2nd jmacleod's comment above.
You need to run "pkcon refresh" before running "pkcon update"