i think the bottom line is that life lists – lists in general – are old and are known to have problems. if you trust your app numbers, they should match up with what you see in the Explore page in the website, and just go with those.
if you really want to understand what the differences are, there are tons of previous threads in this forum that go over this topic, as well as bugs, etc. you could start here: https://forum.inaturalist.org/t/help-with-different-count-number-of-species/11995.
i suggest conversation continue on existing topics, or maybe moderators can figure out a way to consolidate threads somehow…