Hostpot in bridge mode fail radius

Good friends, needed to implement a hotspot (with pppoe everything goes perfect) on an interface in bridge mode and works fine until I try to close a user session manager and always gives me 503 error and not close sessions or eject users who are expiring. Use CCR1036 with 6.18. If I implement the portal interface with no bridge mode works perfectly and runs well radius orders. Can you help? Thank you.