Hi Martin.
Yes, I’m using Version 1.7.18 with exactly the same settings for the simple and complex shortcodes.
If I use the simple version, the tweets pulled are from last month but report as fairly recent in the display.
If I use the complex version, the tweets are accurate.
I wondered if it was because I was using the shortcode within another shortcode used by my page builder but I’ve tried it on its own and I get the same results.
I even tried both the simple and complex together so the results should be identical but they exhibit the same behaviour with the simple shortcode pulling older tweets and the complex shortcode pulling correct tweets.
Kev