Rich ‘elfin’ Pedley,
already searched
but wp-forum is old and not supported for a long time
bbforum is good but not the thing that I see here vishalkhialani,
thanks, yeah That wud be int to know
finally found the solution
on my test platform I had host wmpu-local without dot
thats why when WP tried to set cookie for subdomains browser can’t accept it
because there was .wmpu-local host in set-cookie