Thanks Jekkos for the final debug of ci4-upgrade and the switch to master branch.
Just a small improvement below and allow to manage all urls

setup environment /roo/.env

FIX IN /root/.env environment

CI_ENVIRONMENT = development

.htaccess patch PB force URL on localhot

IN /root/.htaccess force the http://localhost/public

FIX compatible for all URLs or subdirectories

RewriteRule ^(.*)$ %{REQUEST_URI}public/ [R=301,L]

FIX IN /root/public/.htaccess

# if in web root  Do not forget the ? behind index.php
RewriteRule ^([\s\S]*)$ index.php?/$1 [L,NC,QSA]   

https://www.drupal.org/forum/support/post-installation/2016-09-19/how-to-remove-indexphp-from-urls

********** START debug *************
first START
migration from OSPOS with ci3.x, version 3.3.8 to with ci4.x OSPOS version 3.4.0-dev
No bugs found

Gabriel byoosdigital.com