Feed URL breaks when setting "split_the_query"

[rd778]

When I use the Wordpress filter below to split the query for better object caching, the feed URL /feeds/eo-events/ no longer works - the ics file is not created and nothing downloads.

add_filter( 'split_the_query', 'wp_using_ext_object_cache' );

If I comment out the above filter, the feed URL works correctly and the ics file downloads.

I'm raising this here as it seems like this may be a bug - I can't think of any reason why this would be an intended feature?