Used to use phpList about 3 years ago, so not a complete novice.
Installed fresh install and tried to import a CSV file containing mail and a foreign key field (username)
Import works perfectly till say 300 entries and then just stops, ie no activity in browser and if check tables via phpmyadmin, there is no activity either. If try again, it may get to say 400 entries and same non responsive state. Each time it will advance around 100 more entries than previous attempt.
Any ideas where to begin troubleshooting?
Using 3.4.3 .