I could not create storage, then having seen this question answered I could not log back in with username firstname.lastname@example.org.
every time you relaunch the lab, the credentials are subject to change. So, after the 30 minutes allotted, you have to take another set of credentials which will automatically be generated.
Hopefully, this helps.
As Yasushi mentioned, every time you relaunch the lab, the credentials change. In terms of the storage, make sure you use the same location as your lab assigned resource group.