url brocken / become /2F

I upgraded from CI4.1 or 2 (not sure) to CI4.3
I install a fresh installation and copy views, models controllers etc...

I noticed that lot of change break the code specialy the url. Before I had site_url('controller/method') but the url became like
?%2Fen%2Fgestion%2Flogin%2Flogincheck= / --> %2F I notice I have a ? added and = at the end. 
My solution was to replace site_url by base_url and my / stay /
Now I still have the problem with form_open
Example   echo form_open("/login/logincheck");
--> %2Flogin%2Flogincheck=
How to keep url correctly as I want not as codeigniter wants.
Where do I know all code I need to change like site_url is not valid but replaced by base_url

Maybe I just have to find the correct parameter and all will works as before in previous version.

CodeIgniter 4.3