I follow a number of people on twitter and can see the posts from MOST of them on either my laptop or tablet. However there are some whose postings only appear on my laptop.

If I search for their postings on my tablet I can find nothing posted within the last few weeks, although they appear on the laptop ~ any suggestions?

Are you using a browser or an app? I use the Twitter app on my Windows tablet and on my PC and they work fine, even when I swap between different accounts.