LL3.8: Panel icons in the wrong place - unable to move them - how to fix this?

[m654321]

The panel icons for Desktops, Clock, Notes, WiFi & Sound, for some reason got pushed to the left from their normal position on the righthand side of Panel:

https://imgur.com/a/KuDEmvF

I'm unable to move them in the usual way, using mouse 'right-click' then 'move'
Maybe a 'long' separator has gone missing ..
How can I return them to the right place?

Thanks for any help with this.

PS. I'm using LL3.8

[richtea]

Do not select "Move" but "Properties" instead; Separator window should open, then check "Expand".

[m654321]

Do not select "Move" but "Properties" instead; Separator window should open, then check "Expand".

Many thanks for your help - that did the trick 
Have a great day
Mike