2 Inline Headline Blocks to Wrap as 1

I was able to create 2 headline blocks (say using inline flex) and each pulling in data from post meta so that both ACF fields are displayed in 1 line of readable text. Once the device shrinks to mobile, each headline block seem to be wrapped in it’s own “container” turning the 1 line of text into 2 “columns”. Is there a specific way that we need to setup the parent container and each headline element to force these 2 ACF fields to display in 1 readable line even on mobile? We used to be able to do this before the flexbox roll out. What am I missing? Thanks!