On mobile app search page, Switch to People and scroll down a bit, you should see username. Here is screenshot, last item on search is @emstone account.
As for notifications part, we can see reblog notification on your account, what other notification is missing?
Ok, now on search i scrolled to bottom under people i see too, and under All i scroll through hundreds to over a month ago and see reblog and replies. So it looks like #threads notifications are showing out of date order. Sorry to trouble you and thanks for quixk response as usual