I use filtering on my Library within my ipad/iphone quite a bit since you can't sort by tags, etc. I noticed something strange today.
As an example, I have the following tags in my library in Logos (Desktop): to read (24 books), read (16), seminary (14)
When I search on my ipad I type in "mytag: to read" etc, those numbers match the above.
When I search on my iphone I type the same as above and the tag "To Read" has 9 resources and the others won't pull back any.
Seems like searching by mytag may not be working on the iphone?