i googled this error in many ways but only could find irrelevant messages

i am migrating a cakephp 4.2 PHP application to cakephp 5 and only the 'default' database is usable

in my app_local.php i have declared several databases (as i did in cakephp 4) and only the 'default' is working.

when i use /bin/cake schema_cache build --connection default the cache files are generated in tmp/cache/model

BUT any other db defined i try to use i will get the error

Datasource class XXX could not be found.

if i switch the default configuration with another DB name then the cache is generated. it really looks like only one db configuration is taken, the 'default' one

all databases are on the same host, same user, same mysql configuration

if i try to declare the database with code:

ConnectionManager::setConfig('XXX', $config);

$connection = ConnectionManager::get('XXX');

i will get the error that the source is already declared, and if i remove the configuration of the XXX db in app_local.php, then i get back to the error

Missing Datasource

Datasource class XXX could not be found.

i regenerated the composer several times with composer update dumpautoload

other posts about this error are usually very old, wrong configuration or database not accessible, so i don't know if others had the same issue on the latest versions