Searching a forum thread
Tested with Firefox 87 on Win10
Due to the pagination of the threads, a search using e.g. Firefox's search will only search the visible part of the thread. Below the way that you can search the full thread.
The reason why I placed this first is that you quickly can search a thread if something was already posted 
Click on the forum search box in the right top; you can do the search first or you can select the option Search this topic first. Below the result
