“Is the page by any chance a post type archive or any other type of archive page? If yes, than that is the problem. The filtering will not affect the archive pages unfortunately.” Or is that the part your correction is about?
Sort of, it does not officially support that yet – but there are cases when it could actually work. Your case in theory should work regardless if the Events page is an archive page. I can’t say for sure, but it should.
I guess GTAG used numerical values for some of the fields, and might have tighter type casting (where you can’t mix up numeric and text values). In this case, when the EQUALS is used, the database will treat the field value as numerical and typecast it to a number if it’s not – and that of course does not match anything.
As for the “a” character, check the search logic configuration, so that the minimum number of characters for words is set to 1: https://i.imgur.com/IdR5MKh.png
Otherwise a shorter keyword is only partially checked agains the beginnings of the fields.
