How do I stop the list of sitters refreshing and changing when I try to scroll the list in a search?

When I search for a sitter and try to scroll the list of available sitters, very often the list and map refresh so I have to wait and sometimes can't scroll down to see more than the first couple of sitters. Worse than that, sometimes the list and map both change so a sitter's number on the map changes too.

What's going on and how do I stop this?

This is in the web version, not app.

Thanks.