New Plugins Search not progressing through pages of finds

When searching for a new plugin using SEARCH, some searches, such as Calendar display the first page of finds but when I click >> to go to 2 it does that then suddenly redoes the screen and always goes back to page 1, even though there a many more found. If I use >> it will go to and stay at the last page and if I go < it might keep the previous page up.
It work fine in Popular and Recommended. It is obviously to do with the Search function only.
I can’t prove it right now but I suspect on some searches it is OK.

Any suggestions?