If this is reproducible for you (I can install anbox from the beta channel here in the UK), could you please follow the steps outlined in Extremely slow snap downloads and paste the logs on e.g. https://paste.ubuntu.com/
If this is reproducible for you (I can install anbox from the beta channel here in the UK), could you please follow the steps outlined in Extremely slow snap downloads and paste the logs on e.g. https://paste.ubuntu.com/