Follow this steps to update JoomProject from J3 to J4 correctly.
- Make sure to update your joomla website to latest version 3.10.x
- JoomActivities was merged with JoomProject v4+, so you can uninstall JoomAcitivities or make sure is updated to last version before updating to Joomla 4
- Make sure to use the last version of JoomProject for Joomla 3
- Update Joomla 3 to Joomla 4 , read this article: https://docs.joomla.org/Joomla_3.x_to_4.x_Step_by_Step_Migration
- Once website updated to Joomla 4 , go to joomboost downloads and download JoomProject v4+ then install on your updated website or use Joomla updates manager.