to start with I would say this is a question your A-kasse needs to answer.
Yourself or your A-kasse/Jobcenter must find out if its possible to register online as unemployed with the unemployment service in your destination country (like we can in Denmark).
In cases where you can not register online as unemployed, I am sure that COVI-19 quarantine will mean that the 7-day limit can be extended.
The guidance to the law containing the 7-day rule also state that :
“In exceptional cases, the 7-day time limit may be extended in accordance with Article 64 (2). 1, letter b), 3. pkt. in the basic regulation. The unemployment insurance fund (“A-kasse”) can only extend the deadline if there are special circumstances that have meant that the member could not register before the deadline expires, e.g. administrative problems in the other EEA country or closure of the employment service due to public holidays”.
So, I think you must ask your A-kasse to get an extension/exception to the 7-day rule, if you can’t register online.
Let me know if you have comments.
Anders Weber, A-kasser.dk