After I upgrade from version 10.0.3 to version 10.0.4 I can no longer connect. You are now experiencing the error “Bad value for security code. Try again with new value…”
Do you use a bookmark as url ?
Can you try by calling the login url (http://mydolibarr/ without path after the domain name) ?
Same problem for me after update to version 10.0.4 on PHP 7.2. I tried to call login url without path but no changes.
Can’t reproduce (except by entering a bad value for the captchca).
Tested with 10.0.6 and 11.0.1
Try this version too.