Hi
The roundabout is being resurfaced and it appears there will be no through access although the One.network report doesnt seem clear the local newspaper does say to avoid.
One.Network: Causeway one.network
Waze: https://www.waze.com/en/live-map/directions?latlng=60.182785214998106%2C-1.230897903442383
Local news article: Roundabout set to close to traffic for three days | The Shetland Times Ltd
Not sure if you need more info but hopefully this will be useful as that area gets through traffic.