Sheet name tabs vanished

Hi, hope this hasn’t been answered, couldn’t find it.

In Calc sheet labels used to all apear as tabs in the bar at the bottom. Now - build 3.5.0rc3 - they have disappeared, and only the name of the current sheet is shown. After a terrifying moment when I thought I had lost the other sheets in the workbook, I discovered that one can use Edit - Select sheet to switch.
But this is extremely clumsy, as I need to switch a lot of the time.

Can I please have the tabs back - or have I inadvertently hidden them ? - I have cast about, but can find nothing that seems to affect this.

I seem to have solved this - it really is a matter of continuing to click on the separator betwen the sheet name tabs and the slidy thing for moving horizontally across the sheet (I am sure there is a better name for it). If at first you don’t succeed, come back tomorrow when you have more strength in your clicking finger - eventually it will work.