On 02 March 2022, SIF announced the termination of the Mutual Understanding between Switzerland and Liechtenstein of 20/22 October 2020 on the impact of COVID-19 measures on the treatment of cross-border commuters under the DTA on 31 March 2022.
From 01 April 2022, it is therefore no longer applicable and the normal DTA rules apply again.
The notification agreement with reference to the notice given is available here.