Notes "Search" Doesn't Work

Notwithstanding the what now seems to be never ending bugs Apple s/ware has (23 yr veteran and qualified to state this) why is the "search" feature in Notes not preforming as expected?

I have a document that was downloaded off the net and had errors (multiple ppp's). I entered "pp" in search and it highlighted them but as soon as I edited the very first word that had multiple pp's in it my search yellow results showing the "pp" within the text disappeared and other character letters became highlighted instead?

Only solution so far is to quit Notes and re enter "pp" into the search for every single edit I want to make. Basically rendering the whole editing of pp's from the document pointless due to it being too time consuming....

I'm using a week old brand new MacBook Pro on the latest 13.5 OS 🤦‍♂️