Don't have an answer, may have the same problem. trying to install barber_quickstart and stuck in an install loop. documented with screen shots to post. I am shocked you do not provide an easy upload of images -joomshaper should be embarrassed to call itself a joomla shop.
Here are steps and results
1. go to local host
2. select barber_quickstart file package
3. joomla wizard is initiated, start with 'Install Language' screen
4. joomla wizard 'Login Data' screen
5. joomla wizard 'Database Configuration' screen
6. Install executes (joomla progress for ~2m10s)
7. looped back to inital screen 'Install Language'
Never receive 'Congratualtions Joomla is now installed' message nor am I prompted to remove install files. I seem to be stuck in this endless loop. happy to share screen shots if you want to provide me a hosted location to place the file.