Hey - sorry to hear you are having this issue, i guess you are not alone as others are experiencing it themselves. @rcheesley maybe you should put these two posts together: Mautic:iplookup:download ssh console command reports error on line 99 - #6 by andrew_c3
We spun up an instance and got it working immediately. We did install Mautic 6 with composer, maybe you can look at the tutorial we had written up on how to install mautic 6.
Other things i can suggest is to make sure you save your email:password for maxmind in the UI configuration screen.
SSH into your terminal and run the import command /var/www/mautic/bin/console mautic:iplookup:download
see what the results you get there are. if there are no errors, go back to the UI/UX and try and fetch the DB again,
then give it a shot.
Some things to look for are your mautic logs which are found in /var/www/mautic/var/logs/
and maybe your webserver logs (like nginx) /var/logs/nginx/access.log or something like that