I have somewhat similar problem during import a 480MB site.
Import stuck at 7%. A pop up say “..Is your server running?..”.
php configs are set generously.
memory_limit = 512M
post_max_size = 512M
file_uploads = On
upload_max_filesize = 512M
max_execution_time = 6000
Host Provider: Godaddy
Hosting Platform: Window
Any help would be much appreciated.