Hi we are looking into this issue and update on the findings by ASAP, the new image needs to get published and it might take couple of days if everything works as expected.
as a workaround until this gets fixed, you can use the image with the tag mongodb
mcr.microsoft.com/cosmosdb/linux/azure-cosmos-emulator:mongodb
Update : We have published a new image , try with the latest tag
mcr.microsoft.com/cosmosdb/linux/azure-cosmos-emulator:latest