It appears that Friendica My Portal is down, so that might explain why I get zero results when doing a search on Qoto (Mastodon) on the hashtag #PreviouslyFamousTaglines.
However I just found the problem with that theory--even though My Portal is down, Friendica system Outsourced Math COULD find those entries. Hmmmmmmmmm!!
...and I spoke too soon. Outsourced found only two (first two) postings under #PreviouslyFamousTaglines, and there were others.
Hmmmmm again....